1986

Cargo Body/ Chassis/Electrical

Features

IMPORTANT SAFETY NOTICE

Appropriate service methods and proper repair procedures are essential for the safe, reliable operation of all motor vehicles, as well as the personal safety of the individual doing the work. This manual provides general directions for accomplishing service and repair work with tested, effective techniques. Following them will help assure reliability.

There are numerous variations in procedures, techniques, tools, and parts for servicing vehicles, as well as in the skill of the individual doing the work. This manual cannot possibly anticipate all such variations and provide advice or cautions as to each. Accordingly, anyone who departs from the instructions provided in this manual must first establish that he compromises neither his personal safety nor the vehicle integrity by his choice of methods, tools or parts.

As you read through the procedures, you will come across NOTES, CAUTIONS, AND WARNINGS. Each one is there for a specific purpose. NOTES give you added information that will help you to complete a particular procedure. CAUTIONS are given to prevent you from making an error that could damage the vehicle. WARNINGS remind you to be especially careful in those areas where carelessness can cause personal injury. The following list contains some general WARNINGS that you should follow when you work on a vehicle.

• Always wear safety glasses for eye protection.

• Use s::1fety stands whenever a procedure requires you to be under the vehicle.

• Be sure that the ignition switch is always in the OFF position, unless otherwise required by the pro­cedure.

• Set the parking brake when working on the vehicle. If you have an automatic transmission, set it in NEUTRAL unless instructed otherwise for a specific service operation. If you have a manual transmission, it should be in REVERSE (engine OFF) or NEUTRAL (engine ON) unless instructed otherwise for a specific service operation.

• Operate the engine only in a well-ventilated area to avoid the danger of carbon monoxide.

• Keep yourself and your clothing away from moving parts when the engine is running, especially the fan and belts.

• To prevent serious burns, avoid contact with hot metal parts such as the radiator, exhaust manifold, tail pipe, and muffler.

• Do not smoke while working on the vehicle.

• To avoid injury, always remove rings, watches, loose hanging jewelry, and loose clothing before begin­ning to work on a vehicle. Tie long hair securely behind the head.

• Keep hands and other objects clear of the radiator fan blades.

The recommendations and suggestions contained in this manual are made to assist the dealer in improving his dealership parts and/or service department operations. These recommendations and suggestions do not supersede or override the

provisions of the Warranty and Policy Manual, and in any cases where there may be a conflict, the provisions of the War­ranty and Policy Manual shall govern.

The descriptions, testing procedures, and specifications in this handbook were in effect at the time the handbook was approved for printing. Ford Motor Company reserves the right to discontinue models at any time, or change specifications, design or testing procedures without notice and without incurring obligation. Any reference to brand names in this manual is intended merely as an example of the types of tools, lubricants, materials, etc. recom­mended for use. Equivalents if available may be used. The right is reserved to make changes at any time without notice.

Copyright© 1985 Ford Motor Company

[ TABlE OF CONTENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

CHASSIS FEATURES

Diaphragm Spring Clutch ..................................... .' ............... 3 Power Steering Pump ....................................................... 11 Power Steering Gear ........................................................ 16 Steering Column ........................................................... 18 Air Over Hydraulic Brakes .................................................... 19 Suspension System ......................................................... 40 Front Axle ................................................................. 42 Cab Tilt Mechanism ......................................................... 44 5-Speed Transmission ....................................................... 47 Wheel Nuts ................................................................ 48 Cooling System ............................................................ 48

ELECTRICAL FEATURES

Charging System ........................................................... 50 Electrical System and Wiring Connectors ....................................... 54 Steering Column Switches ................................................... 55

BODY FEATURES

Heating and Ventilation System ............................................... 58

POSTTEST .................................................................... 63

1

INTRODUCTION/OBJECTIVES

INTRODUCTION This manual highlights the body, chassis, and elec­trical service features of the Ford Cargo 6000 and 7000 trucks. Because the Cargo is a European/ Brazilian vehicle, many of the features and com­ponents are new to North America.

This program is designed to build upon your cur­rent knowledge of the service procedures perform­ed on other components. Detailed information is provided for those features and components which are new.

Familiarize yourself with the descriptions, opera­tions, and service procedures contained in this manual. For detailed, step-by-step assembly and disassembly instructions and specifications, always consult the Shop Manual and current Service Bulletins.

OBJECTIVES After studying the product changes described in this manual and practicing the related service pro­cedures on the appropriate vehicle, the technician will be able to do the following:

• Identify and explain the major body, chassis, and electrical features of the Ford Cargo truck.

• Identify the components in the hydraulic diaphragm spring clutch system and explain their operation and basic service procedures (adjustments, bleeding, on-vehicle leakage checks).

• Identify the major components in the power steering system (pump, gear, steering column) and explain their new features and basic service procedures.

2

• Identify and explain the operation of the major components in the air over hydraulic brake system. ·

• Explain and perform basic service procedures on the components in the air over hydraulic brake system.

• Identify and explain the major features of the Cargo suspension system.

• Identify and explain the major features of the Cargo front axle. ·

• Identify and explain the operation of the cab tilt mechanism, including adjustment of the Jock assembly.

• Identify and explain the linkage adjustments for the Clark 5-speed transmission in the Cargo truck.

• Identify the major components in the cooling system and explain their operation.

• Identify and explain the operation of the major components in the charging system and under­stand basic service procedures.

• Understand and explain the major differences in the Cargo electrical system and wiring connectors.

• Identify the major components in the Cargo heating and ventilation system, explain their operation, and understand basic service pro­cedures and diagnosis for the system.

DIAPHRAGM SPRING CLUTCH

DESCRIPTION AND FEATURES

o The diaphragm spring clutch in the Cargo truck is a pull-type hydraulically-actuated clutch that uses a diaphragm spring to load the driven disc between the pressure plate and the flywheel.

• The pull-type diaphragm spring design provides a more modern and efficient clutch that is the state of the art for today' s medium vehicles.

-7A543· CLUTCH MASTER CYLINDER

Hydraulic System

• The diaphragm spring clutch and its respective linkage and controls are all hydraulic and self­adjusting (Figure 1). The hydraulic system is composed of these major components:

- Master cylinder

Clutch pedal

- Slave cylinder

• The master cylinder is actuated by the clutch pedal pushrod. The slave cylinder is attached at the transmission.

-7511-

-7A508-SLAVE CYLINDER ASSEMBLY

CLUTCH RELEASE LEVER

-7510-CLUTCH RELEASE SHAFT

Figure 1 - Hydraulic Clutch Assembly

3

DIAPHRAGM SPRING CLUTCH

Master Cylinder

• The master cylinder (Figure 2) is located behind the hood adjacent to the foot brake control valve.

• The master cylinder and reservoir supply the hydraulic fluid needed to operate the system. At rest position there is no pressure in the master cylinder. The fluid from the reservoir fills the area in front of the piston through the supply orifice in the cylinder housing.

• When the clutch pedal is depressed, the piston is forced forward by the pushrod. As the piston moves forward, the seal blocks the supply orifice and hydraulic fluid flows out of the master cylinder and through the system line.

• When the clutch pedal is released the return spring pushes the piston back to the rest posi­tion. Because fluid return is slower than piston return, a mild vacuum is formed which forces the fluid that is behind the piston to flow through the bleeder holes in thehead of the piston. This

SUPPLY ORIFICE

OUTLET PORT

RETURN SPRING

fluid bends the lips of the seal away from the cylinder wall and enters into the chamber in front of the piston. This flow of liquid through the bleeder holes prevents the possible entry of air by keeping the cylinder filled at all times.

• The fluid reservoir is mounted to the master cylinder housing. It is made of a translucent plastic which permits instant fluid level check­ing without removing the filler cap.

Clutch Pedal

• The clutch is actuated by pressing the clutch pedal (Figure 3) which is connected to the pushrod of the master cylinder.

• The clutch pedal range of motion is controlled by a stop bolt installed in the cab bulkhead. This stop bolt is used to adjust the clutch pedal travel range at manufacture, and should not be ad­justed in service, unless new pedal parts are in­stalled. Adjustment procedures for rebuild will be covered later in this manual.

RESERVOIR

PUSHROD SEAL

Figure 2 - Master Cylinder Assembly

4

PUSH ROD

STOP BOLT

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DIAPHRAGM SPRING ClUTCH

Slave Cylinder

• The slaye cylinder (Figure 4) is installed on the transmission housing with a mounting bracket.

• The slave cylinder receives hydraulic pressure from the master cylinder through the fluid line. This pressure pushes against the piston, driving the piston and pushrod forward and actuating the clutch release mechanism.

• The preload springs preload the release bearing, ensuring automatic adjustment by the slave cylinder.

Automatic Adjustment

CAB ___....

• As the friction material on the clutch disc wears, the slave cylinder and master cylinder will com­pensate for the additional clearance between the disc and the flywheel. Therefore, no pushrod ad­justment is needed during the life of the clutch disc.

BULKHEAD

Figure 3 - Clutch Pedal

BLEEDER SCREW

PRELOAD SPRINGS

HOUSING

SEAL

DUST BOOT

Figure 4 - Slave Cylinder Assembly

5

0

DIAPHRAGM SPRING CLUTCH

Clutch Assembly

• The outstancling feature of this new clutch design is the diaphragm spring that is used in place of the coil springs found on most truck clutches. The diaphragm spring is a round disc with fingers that extend toward the center (Fignre 5). It is constructed in a dish-like shape which provides the powerful bellville spring action.

OPERATION

• When the clutch is in the engaged position, the diaphragm spring is held tightly against the pressure plate. The clutch disc is clamped firm­ly between the flywheel and the pressure plate in this position (Fignre 6).

• When the clutch pedal is depressed, hydraulic pressure is transmitted from the master cylinder to the slave cylinder. The slave cylinder actuates the clutch release lever and turns the release shaft (Figure 6).

• As the release shaft turns, the release lever pulls back on the release sleeve and diaphragm spring fingers, unloading the bellville spring, and permitting the pressure plate to move away from the clutch disc. The transmission input

6

shaft and clutch disc are disengaged from the engine and the transmission may be shifted into another gear. ·

• Because of the dish-like shape of the diaphragm spring, it requires a great amount of force to pull the spring away from the disc. So when the clutch is released, the diaphragm spring springs back to its original position. Pressure is once again applied to the pressure plate and the clutch disc is held firmly against the flywheel.

Figure 5 - Diaphragm Spring

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-7563-CLUTCH COVER AND PRESSURE PLATE ASSEMBLY

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SERVICE PROCEDURES

• Check the condition of the clutch pedal. Check the pedal rubber shoe, stop bolts, clutch pedal free travel, and the play between the pedal and master cylinder pushrod.

• Check for leaks along the hydraulic fluid line. Replace line if necessary.

• Check the master and slave cylinders for cracks or other damage. Check the slave cylinder push­rod pin for wear. If there is any play, replace the slave cylinder.

Clutch Pedal Adjustment

• Adjust total pedal travel so that the pedal will come close to, but not touch, the bulkhead when the pedal is fully depressed. Clutch pedal free travel should be 5-10 mm (.2-.4 inches) from the upper stop bolt (Figure 7). Adjustments are made by turning the upper and lower stop bolts.

STOP BOLT

CAB BULKHEAD

STOP BOLT

~--1- 5-10MM -- ____ f -(.2-.4 INCHES)

CLUTCH PEDAL

Figure 7 - Clutch Pedal Adjustment

8

System Bleeding

• System bleeding eliminates air bubbles that may enter the hydraulic fluid and cause insufficient pedal travel or a spongy pedal; it also cleans the system as it eliminates old fluid. To bleed the system follow these procedures:

1. Remove the reservoir filler cap.

2. Fill the reservoir with fluid up to the max­imum level mark.

3. Remove the slave cylinder bleeder dust cover and install one end of a transparent hose. Place the other end of the hose in a clean container, above bleeder level.

4. Depress the clutch pedal several times, then hold it down.

5. While the pedal is depressed, open the bleeder screw to let fluid flow out. Check to see if fluid contains air bubbles.

6. Close the bleeder screw and release the clutch pedal.

7. Repeat steps 4, 5, and 6 until all the air bub­bles in the fluid are eliminated.

8. Close the bleeder screw and tighten.

9. Remove the hose and reinstall the bleeder dust cover.

10. Check the reservoir fluid level. If it is not filled to specifications, fill with new fluid. DO NOT OVERFILL.

DIAPHRAGM SPRING CLUTCH

Clutch Alignment Procedures

• Alignment procedures for the Cargo diaphragm spring clutch have not changed significantly from those of other applications. The same align­ment Tool No. D79T-7550-B may be used to align the clutch properly when installing. Refer to the Shop Manual for complete removal and installa­tion instructions.

-6375-FLYWHEEL

·7600· PILOT BEARING

-7550-CLUTCH DISC

-7510-CLUTCH RELEASE SHAFT

Figure 8 - Diaphragm Spring Clutch - Exploded View

9

-7590-

-7500-CLUTCH HOUSING

CLUTCH RELEASE SHAFT STUD

DIAPHRAGM SPRING CLUTCH

Slave Cylinder Adjustment

• Whenever the slave cylinder is removed and then reinstalled, the length of the pushrod must be adjusted. The adjustment procedures are as follows:

1. Install the slave cylinder on the mounting bracket attached to the transmission case (Figure 9).

2. Loosen the pushrod Jock nut and adjust the length of the pushrod so that the distance between the lower slave cylinder mounting hole and the pushrod Jock nut slot is 144-147 mm (5.6-5.8 in.) (Figure 10).

DIAGNOSIS

• For full diaguosis tables, refer to the Shop Manual.

-7511-CLUTCH RELEASE LEVER

PUSHROD FORK

·7A508-SLAVE CYLINDER

-7510-RELEASE SHAFT

BLEED SCREW

SLAVE CYLINDER HOUSING

144-147 mm (5.6-5.8 in.)

SLOT

PUSHROD LOCK NUT

0

Figure 10 - Slave Cylinder Adjustment

-7B532-MOUNTING BRACKET

TRANSMISSION

Figure 9 - Slave Cylinder Installation

10

POWER STEERING PUMP

DESCRIPTION

• Power steering will be a standard feature on all Cargo vehicles.

• The Cargo truck line utilizes a constant displace­ment slipper vane power steering pump. The pump is gear driven from the engine.

• The steering fluid reservoir is remote to the pump and mounted to a bracket on the chassis (Figure 11). The pressure line and return line carry fluid to and from the power steering gear. A large hose supplies the fluid from the reser­voir to the pump.

SERViCE PROCEDURES

• The power steering pump may be serviced as an assembly or kits are available to replace dam­aged components. See the Shop Manual for removal and installation procedures.

·3A742· DRIVE GEAR

PRESSURE LINE

• The fluid level in the reservoir should be checked at regular intervals (about every 3000 miles) .. Check the fluid level with the engine off. Use the HOT or COLD markings on the dipstick, depending on the fluid temperature.

- Use COLD for checking at room temperature 70°F (20°C).

- Use HOT for normal operating temperature 175°F (80°C).

The fluid level must be between the ADD and FULL markings on the dipstick. Add automatic transmission fluid DEXRON II® or equivalent if necessary.

-3531-RESERVOIR

STEERING GEAR

Figure 11 - Power Steering Pump installation

11

POWER STEERING PUMP

• To avoid air intake, all power steering line con­nections should be checked for tightness and leaks. Refer to the Shop Manual for specifica­tions and procedures.

• To test for leaks follow these procedures:

1. With the engine off, wipe the power steer­.ing lines, steering gear, and reservoir to aid in leak detection.

2. If the power steering fluid does not already include dye, mix one teaspoon of oil-soluble analine dye into the steering fluid and fill the reservoir to specification if necessary.

3. With the engine running at 1000-1500 rpm, turn the steering wheel all the way to the right and left several times.

CAUTION: TO PREVENT DAMAGE TO THE PUMP, DO NOT HOLD THE STEERING WHEEL IN THE FAR LEFT OR FAR RIGHT POSITION FOR OVER 5 SECONDS.

4. Turn off the engine and check for leaks. Ser­vice as necessary.

Figure 12 - Power

12

NOTE: After any major power steering system or component overhaul, the system should be purged of old fluid and the oil filter discarded. New fluid and a new filter should then be installed.

• If bubbles are visible in the steering fluid, bleed the air from the system by following these procedures:

1. Check the fluid level as previously describ­ed. Add fluid if necessary.

2. Run the engine until the fluid reaches nor-mal operating temperature. ·

3. Turn the steering to full right and full left several times.

CAUTION: TO PREVENT DAMAGE TO THE PUMP, DO NOT HOLD THE STEERING WHEEL IN THE FAR LEFT OR FAR RIGHT POSITION FOR OVER 5 SECONDS.

4. Recheck the fluid level and add DEXRON II® or equivalent if necessary.

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( POWER STEERING PUMP

Power Steering System Tests

• Hydraulic pressure/flow tests may be conducted using the Rotunda Analyzer Kit 014-00230 which consists of a pressure gauge, flow meter, shut­off valve, thermometer, hose, and adapter attachments.

NOTE: Possible contamination of the power steering system fluid may cause permanent damage to the gauges and instruments incor­porated in the analyzer. If there is a possibility of burned fluid or metal filings in the fluid, the power steering system should be purged before connecting the power steering analyzer.

Test Preparation

1. To connect the analyzer into the steering system, disconnect the pressure line from the connector at the pump (Figure 13).

2. Thread the proper adapters to the pump connector and to the pressure line.

EXISTING HOSE (PRESSURE) ~

STEERING GEAR SHUT-OFF VALVE

ANALYZER

Figure 13 - Analyzer Connections

13

3. Connect the analyzer to the adapters and tighten both connections to the proper tor­que (refer to chart in kit). Be sure the analyzer line at the shut-off valve end is con­nected to the steering gear end of the vehi­cle power steering system.

4. Fully open the shut-off valve, start the engine, and purge the air from the power steering system by steering to the full left and right turn position several times. Shut off the engine and check connections for leaks.

5. Check for proper fluid level at the reservoir and add or remove fluid as required. Re­check for air in the system by restarting the engine. Partially close the shut-off valve and view the pressure gauge. If the gauge needle vibration is excessive, too much air remains in the system. (Repeat step 4 if necessary.)

6. Install the thermometer provided with the analyzer kit in the reservoir and connect the tachometer to the engine.

Test Procedures

• Check the power steering system back pressure following these procedures:

1. Fully open the analyzer shut-off valve.

2. Put the front wheels in the straight ahead position, put the transmission in neutral, and engage the parking brake.

3. Start the engine and run it at 2200 rpm.

4. When the fluid temperature reaches 55°C (130°F) record the flow and temperature.

a. If flow is below 13.2 Lpm (3.5 gpm) check to see if the correct pump is installed for the truck being tested. If the correct pump is installed, continue testing to find the problem.

b. If pressure exceeds 552 kPa (80 psi) check the lines for kinks or obstructions. If none are found and pressure remains high, continue testing to find the problem.

POWER STEERING PUMP

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1. SET PIN 14. VALVE PISTON 2. PUMP HOUSING 15. TYPE PLATE 3. NEEDLE BEARING 16. HOOK SPRING RING 4. ROTARY SHAFT SEAL 17. COVER 5. RETAINING RING 18. BACK-UP RING 6. DEEP GROOVE BALL BEARING 19. O·RING 7. CIRCLIP 20. PRESSURE SPRING 8. DRIVESHAFT 21. FACEPLATE, COVER SIDE 9. KEY 22. O·RING

10. NUT 23. BACK-UP RING 11. SCREW PLUG 24. ROTOR SET 12. SEAL RING 25. FACEPLATE, DRIVE SIDE 13. PRESSURE SPRING

Figure 14 - Power Steering Pump - Exploded View

14

POWER STEERING PUMP J • Check the pump for minimum efficiency flow

using these procedures:

1. Decrease the engine speed to 600 rpm.

2. Slowly close the shut-off valve to build pressure to 8300 kPa (1200 psi).

3. Record flow with temperature at 55°C (130°F).

a. If flow is below 8.3 Lpm (2.2 gpm):

check to see if the correct pump is in­stalled for the truck being tested.

the pump may require repair or replacement, especially if the flow was insufficient in the last test.

• Check the pump for pressure relief valve opera­tion using these procedures:

1. Run the engine at 600 rpm.

2. Completely close and partially open the shut­off valve 3 times.

15

CAUTION: Do not hold the shut-off valve closed • for more than 5 seconds. Failure to follow this caution will result in damage to the pump and/or gear.

3. Read the pressure when the valve is fully closed.

a. If pressure is below 12,500 kPa (1800 psi) or exceeds 15,500 kPa (2232 psi), clean or replace the pressure relief valve. Refer to the appropriate section in the Shop Manual.

• Refer to the following chart for specifications on allowable pressures for the power steering system.

IRPM Uters/ Gals./ kPa psi Min. Min.

600 8.3 2.2 8300 1200

2200 13.2 3.5 - -

POWER STEERING GEAR

DESCRIPTION

• The integral type Bendix power steering gear ensures very light steering and minimum driver effort, along with great maneuverability.

• The steering shaft attaches to the steering gear at the input shaft (Figure 15). Turning action is

-3C529-STEERING COLUMN ASSEMBLY

-3N503· POWER STEERING GEAR

-3590-PITMAN ARM

transmitted from the input shaft to the steer­ing gear output shaft and pitman arm through a worm shaft and gear assembly.

• The power steering gear is mounted to the frame sidemember by three attaching bolts.

~ -3304-DRAG LINK

Figure 15 - Power Steering Gear Assembly

16

[ POWER STEERING GEAR J SERViCE PROCEDURES

System Bleeding

• To bleed the hydraulic power steering system, follow these procedures:

1. Raise the front of the vehicle so that the wheels are off the ground.

2. Remove the drain plug from the steering gear lower housing and then turn the steer· ing wheel all the way to the left.

3. Run the engine for a maximum of 10-15 seconds until all the oil has drained from the. reservoir and pump.

4. Turn off the engine and turn the steering fully to the left and right until all the oil has. been drained.

5. Clean the reservoir and replace the oil filter.

• More detailed information, as well as service and diagnosis procedures for the power steering gear may be found in a separate publication.

Figure 16 - Bendix Power Steering Gear

17

STEERING COLUMN

DESCRIPTION

• The steering column system in the Cargo vehicle is composed of the following major components (Figure 17):

Steering wheel

Steering shaft

Steering column

Column shroud

Universal joint

Column Gaiter

• The steering wheel is in mesh with serrations on the steering shaft. It is secured to the steer­ing shaft by a locking nut. The serrations allow for easy repositioning of the steering wheel on the steering shaft.

LOCKING NUT

-3678-COLUMN BR.ACt(ET

SLIP YOKE/UNIVERSAL JOINT

• The steering shaft extends through the steering column (attached to the panel) and is supported on it bY. two ball bearings. The lower end of the steering shaft is covered by the column shroud and extends through the cab floor.

• The plastic column shroud is secured to the cab floor by pop rivets. A plastic seal is installed be­tween the cab floor and the column shroud to prevent dust from entering the steering assembly.

• The universal joint is a lube-for-life design and does not require periodic lubrication.

• The splined steering shaft/slip yoke interface re­quires periodic lubrication which can be achieved with a grease nipple located on the universal joint/slip yoke.

-3A526-STEERING SHAFT

LOWER /f...---- COWMN SHROUD

GREASE NIPPLE

Figure 17 - Steering Column Assembly

18

r STEERING COLUMN

• A universal joint connects the steering shaft to the steering gear input shaft (Figure 18). The upper slip yoke of the universal joint slides on the splined lower end of the steering shaft to allow for cab tilt and articulation. The universal joint is non-replaceable. If it is broken or dam· aged, the slip yoke/universal joint assembly must be replaced.

Steeril'lg Columl'l Switches

• There are three switches located on the steer· ing column.

- Combined turn indicator/horn and headlamp flash switch

- Windshield wiper/wash switch

- Ignition switch with steering lock

• For more information on the steering column switches, refer to the "Electrical Features" section.

STEERING GEAR INPUT SH.AFT (UNDER UNIVERSAL JOINT)

Figure 18 - Steering Shaft to Steering Gear Connection

AIR OVER HYDRAULIC BRAKE SYSTEM

IDESCR!IPTION ANID FEATURES

• The Cargo 6000 vehicle is equipped with air over hydraulic front disc and rear drum brakes (standard). As an option, the Cargo 7000 may be equipped with a full air brake system, in· eluding S-Cam type air brakes (Figure 19).

• The standard Cargo brake system (Figure 20) is essentially a combination of two brake systems -hydraulic and air. The parking brake system is all air and features a newly designed spring brake chamber.

• The air portion of the Air Over Hydraulic Brake System contains the following components:

- Single piston compressor

- Governor

Reservoirs

Safety valves

Single check valves

- Double check valves

19

Low pressure indicators

Foot control valve

• The front disc brakes and rear drum brakes in the Cargo system are all hydraulic with air over hydraulic activation. The hydraulic portion of the system includes the following major components:

- Air/Hydraulic intensifiers

- Pressure differential warning switch

- Hydraulic front disc brakes

- Hydraulic rear drum brakes

• The air parking brake system of the Cargo vehi­cle is composed of the following components.

- Parking brake control valve

- Double check valves

- Quick release valve

- Spring brake chambers

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DUAL AIR GAUGE

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QUICK RELEASE VALVE

- I 1/8 J.D. HOSE

z 0 ..J )-z ~ -

•- I 8~~ • SWITCH

3/8 J.D. HOSE I \. SINGLE CHECK ~! '\c=\=( C: VALVE

PRESSURE DIFFERENTIAL WARNING VALVE

' I PRIMARY AIR TANK I

3/8 NYLON

1/2 NYLON / ----------

I I I

" I DOUBLE CHECK DRAINCOCK I VALVE I

"'\ 112 NYLO~---------··"/ ..... _______ _ 3/8 NYLON

luj w ,... rn "!

irl w ,... rn "! -

PARKING BRAKE CONTROL VALVE

1/4 STEEL o"" ,~.v

,,,. ~ DRUM BRAKE

PARKING BRAKE LOW PRESSURE SWITCH

PRIMARY AIR SYSTEM SECONDARY AIR SYSTEM --­PARKING BRAKE AIR SYSTEM ---

SPRING BRAKE • ~ CHAMBER ~~

)> -::Ill ~ m :D :I: -< c ::Ill

~ r -0 m ::.tiJ )>

" m

~ m s

~·,

AIR OVER HYDRAULIC BRAKE SYSTEM

Air System

Compressor - Description

• The function of the air compressor (Figure 21) is to build up and maintain the required amount of air pressure in the air reservoirs of the sup­ply system.

• The compressor in the Cargo vehicle is a belt driven, single cylinder, reciprocating piston design. Lubrication of the bearings is by an oil feed off the engine main lubrication system. The compressor is cooled by coolant from connections to the engine cooling system.

• The compressor is constructed from two major assemblies, the head and the crankcase. The head houses the inlet, discharge, and unloader valving and is installed on the upper portion of the crankcase. The crankcase is a one-piece casting combining the cylinder block and the crankcase. The upper portion of the casting houses the cylinder bore and piston; and the lower portion, the crankshaft and main bearings (Figure 22).

• The compressor operates while the engine is run­ning, but it compresses air only when the unloader piston in the compressor is not pres­surized by the governor.

GOVERNOR TUBE

COOLANT SUPPLY

COOLANT_-~t:i;: RETURN

Figure 21 - Air Compressor

22

CYLINDER HEAD ASSEoMBLY

GASKET

PISTON RINGS

OIL

PISTON RINGS

CONNECTING ROD

,_ " _GOVERNOR cy---·· GASKET

CRANKSHAFT END COVER ASSEMBLY

Figure 22 - Compressor - Exploded View

Compressor - Operation

• The compressor operates as follows (Figure 23).

As the compressor piston is retracted (mov­ed downward), the inlet valve is unseated and air is drawn in through the inlet port.

With the piston moving upward, the air is compressed. The air inlet valve is seated and thus keeps the air from leaving the cylinder through the inlet valve. As the air is com­pressed further, it overcomes the spring force of the discharge valve and the compressor air is forced through the discharge line and into the reservoir.

As the compressor piston moves downward, the discharge valve is returned to its seat, air is drawn into the cylinder by way of the in­let valve, and the cycle begins again.

AIR OVER HYDRAULIC BRAKE SYSTEM

DISCHARGE VALVE

INLET ADAPTOR AND ELBOW

UNLOADER INLET AND PISTON EXHAUST VALVE

RESERVOIR

Figure 23 - Compressor Operation Schematic

• When air pressure in the air reservoir reaches the governor cut-out setting of 793-861 kPa (115-125 psi), the governor opens and allows air to the compressor unloader piston. The unloader piston is lifted, thus moving the air inlet valve off its seat. With the inlet valve unseated, air is pumped back and forth past the inlet valve.

• As reservoir pressure is reduced during brak­ing, the governor pressure drops to its cut-in pressure setting of 620-772 kPa (90-112 psi) (89-172 kPa or 13-25 psi below the cut-out pressure) and the governor closes and exhausts the air below the unloader piston. The spring then moves the unloader piston downward, the inlet valve is seated, and the compressor cycle is restarted.

Governor - Description

• The governor (Figure 24), operating in conjunc­tion with the compressor unloading mechanism, automatically controls the air pressure in the air brake or air supply system. It maintains the desired, predetermined maximum and minimum pressures.

23

• The compressor runs continually while the engine runs, but the actual compression of air is controlled by the governor actuating the com­pressor unloading mechanism. This stops or starts compression when the maximum or mini­mum reservoir pressures are reached.

• The D-2A governor used in the Cargo has a piston upon which air pressure acts to overcome the pressure setting spring. This controls the in­let and exhaust valve to either admit or exhaust air into or out of the compressor unloading mechanism.

• The D-2A governor is mounted directly to the compressor. A copper tube supplies air to the unloader valve in the head.

• The governor on the Cargo vehicle is a non­adjustable design. The governor calibrations have been pre-set and should not be tampered with.

• Porting of the governor consists of 3 reservoir ports (1/8 inch NPTF), 3 unloader ports (1/8 inch NPTF), and 1 exhaust port (1/8 inch NPTF).

EXHAUST PORT

RESERVOIR PORTS (3)

UNLOADER PORTS (3)

EXTERIOR VIEW

Part No. 2885

Figure 24 - Governor

AIR OVER HYDRAULIC BRAKE SYSTEM

Governor - Operation

• The governor operates in the following manner (Figure 25).

Air pressure from the reservoir enters the governor at one of its reservoir ports and acts on the area of the piston and beneath the in­let and exhaust valve.

As air pressure builds up, the piston moves against the resistance of the pressure setting spring.

The piston and inlet and exhaust valve move up when the reservoir air pressure reaches the cut-out setting of the governor. The ex­haust stem seats on the inlet and exhaust valve, and then the inlet passage opens.

Reservoir air pressure then flows by the open inlet valve, through the passage in the piston, and out the unloader port to the compressor unloading mechanism.

Air also flows around the piston and acts upon the additional area of the piston. This added force assures a positive action, and fully opens the inlet valve.

As the system reservoir air pressure drops to the cut-in setting of the governor, the force exerted on the piston by the air pressure will be reduced. The pressure setting spring will push the piston down, the inlet valve will close, and the exhaust will open.

INLET AND EXHAUST VALVE

INLET·EXHAUST __ _ VALVE SPRING

With the exhaust open, the air in the unloader line will escape back through the piston, through the exhaust system, and out the exhaust port.

Reservoirs

• The reservoir is a storage tank; its function is to provide a volume of compressed air for brak­ing which will be adequate to operate the brake chambers, intensifiers, and auxiliary devices. It also provides a location in the system where the air that is heated by compression may be cooled and the water vapor condensed. The reservoirs are mounted within the chassis sidemembers and retained by metal straps.

• The primary reservoir is the air source for the intensifier which operates the rear drum brakes. The front disc brake intensifier is supplied by the secondary reservoir. The supply tank provides the air pressure for both the primary and second­ary reservoirs.

• Draincocks with lanyards are installed on the bottom of each reservoir to provide a convenient means of draining the condensation that normally forms in the reservoirs.

PRESSURE SETTING SPRING

UPPER SPRING SEAT

RETAINING RING

COVER

SPRING GUIDE

~~~~~l~ST STEM

Figure 25 - Sectional View of Governor

24

[ AIR OVER HYDRAULIC BRAKE SYSTEM

Safety Valve

• The safety valve (Figure 26) protects the air brake system against excessive air pressure build up.

• The safety valve consists of a spring loaded ball valve that is constantly subjected to reservoir pressure. If reservoir pressure rises above the valve pressure setting (determined by the force of the spring), the valve will exhaust the reser­voir pressure to the atmosphere.

• A safety valve setting of 1034 kPa (150 psi) is used, and is not adjustable. If system pressure rises to approximately 1034 ± 48 kPa (150 ± 7 psi), air pressure would force the ball valve off its seat. Reservoir pressure would then be re­leased to the atmosphere through the exhaust port in the safety valve housing.

RELEASE PIN

EXHAUST PORT

PIPE THREAD--<>-~j__jj

Part No. 2A550

Figure 26 - Safety Valve

25

• When reservoir pressure decreases sufficiently the spring force will seat the ball check valve, sealing off reservoir pressure. This occurs at 930 kPa (135 psi) for the 1034 kPa (150 psi) setting.

• It is important to note that the desired pressure setting of the safety valve is determined by the governor cut-out pressure. The opening and clos­ing pressures of the safety valve should always be in excess of the governor cut-out pressure setting. The pressure setting is stamped on the lower wrench flat of the valve.

Single Check Valve

• The single check valve (Figure 27) protects the reservoir in the event of air pressure loss in the compressor or the supply tank.

• The single check valve allows air to flow in only one direction and prevents the flow of air in the reverse direction. An arrow indicating the direc­tion of air flow is cast into the body of the valve.

• The single check valve operates in the follow~ ing manner:

Airflow in the normal direction moves the valve disc from its seat, and the flow is unobstructed.

Flow in the reverse direction is prevented by the seating of the spring loaded disc.

DISC

WASHER

VALVE SEAT

Part No. 28170

Figure 27 - Single Check Valve

AIR OVER HYDRAULIC BRAKE SYSTEM

Double Check Valve

• A double check valve (Figure 28) directs a flow of air into a common line from either of two sources, whichever is at the higher pressure.

• A double check valve is used to direct air flow for specific functions or to select the higher pressure from either of two sources of air as a supply source.

• As air under pressure enters either valve inlet port, the moving shuttle responds to the higher pressure and seals the opposite port. The air then flows out the delivery port of the double check valve. The position of the shuttle will reverse if the pressure levels are reversed.

• Double check valves are designed so that the shuttle will never impede the backflow of air in the exhaust mode.

Low Pressure Indicator

• The low pressure indicator is a safety device designed to warn the driver whenever air pressure in the system drops below 414 kPa (60 psi), the safe minimum for normal vehicle operation.

• A low pressure indicator is installed in each of the air supply lines at the foot control valve.

INLET~

OUTLET PORT

INLET PORT

Part No. 2K119

Figure 28- Double Check Valve

26

Foot Control Valve

• The E-6 foot control valve (Figure 29) is mounted on the vehicle front panel behind the hood and is operated by a brake pedal and pushrod assem­bly. The valve provides two separate supply and delivery circuits to control the primary and secondary brake systems.

• The air from the supply tanks is metered by the foot control valve as the driver applies the pedal during a brake stop. This provides the driver with a graduated control for applying and releas­ing the vehicle brakes.

• In dual circuit valves, such as this one, the two circuits are separated within the valve, although operated by a single pedal. This ensures that if one circuit fails, the other will continue to function.

Figure 29 - Foot Control Valve

AIR OVER HYDRAULIC BRAKE SYSTEM 1 Hydraulic System

Air/Hydraulic intensifier- Description

• The air/hydraulic intensifier (Figure 30) is used to convert air pressure to hydraulic pressure to apply the brakes. The air pressure for the opera­tion of the intensifier is supplied from the air reservoir.

• There are two air /hydraulic intensifiers on the Cargo vehicle - one for the front disc brakes and another that operates the rear drnm brakes.

• A master cylinder containing hydraulic fluid is bolted to the end of the air chamber. The brake fluid reservoir is mounted to the top of the master cylinder and it provides the hydraulic fluid required to compensate for a worn out lining condition.

MASTER CYLINDER

• The diaphragm area of the air chamber is ap­proximately 17 times the master cylinder piston area; so 689 kPa (100 psi) of air pressure pro­duces approximately 11,720 kPa (1, 700 psi) of hydraulic pressure, a 17:1 ratio.

• The master cylinder reservoir cap incorporates a sensor that will activate a light in the cab if the brake fluid level gets too low. The sensor works with a float that makes a constant con­nection with the cap assembly (Figure 31). When the fluid falls to a level that is too low, the float will break the connection and a light in the cab will alert the driver of the condition.

Figure 30 - Air I Hydraulic Intensifier

27

AIR OVER HYDRAULIC BRAKE SYSTEM

Air/Hydraulic lntensifer- Operation

• The air /hydraulic intensifier is activated by air pressure from the reservoirs. Compressed air enters the air chamber through the inlet port and is applied to the diaphragm in the air chamber (Figure 31). The air pressure pushes the diaphragm against the pressure plate and pushrod assembly. The pushrod activates the piston in the master cylinder and hydraulic pressure is supplied to the front and rear brakes.

• When the air pressure is released from the chamber, the return spring reverses the move­ment and the intensifier returns to its original state.

Rear Drum Brakes - Description

• The rear hydraulic drum brake system consists of two brake shoe and lining assemblies, a wheel cylinder I adjustment assembly, and a wheel cylinder/parking brake expander assembly (Figure 32).

• The wheel cylinder I adjuster acts as a conven­tional wheel cylinder with auto-adjusters which maintain a specified lining-to-drum clearance. The wheel cylinder I parking brake expander acts as a conventional wheel cylinder and it also ex­pands and releases the shoes for parking.

SENSOR CONNECTOR

AIR INLET PORT

PRESSURE +H-ft,..[ PLATE

DIAPHRAGM

AIR CHAMBER

CLAMP BAND

RETURN SPRING

0

MOUNTING BRACKET

MASTER CYLINDER PISTON

MASTER CYLINDER

AIR CHAMBER PUSHROD ASSEMBLY

Figure 31 - Air/Hydraulic Intensifier Sectional View

28

FLUID LEVEL SENSOR FLOAT

TILT VALVE

Part No. 28571

AIR OVER HYDRAUliC BRAKE SYSTEM

Rear Drum Brakes - Operation

• When the brake is applied, brake fluid pressure in the adjuster wheel cylinder forces the pistons outward, forcing the shoes against the drum. At the same time in the expander wheel cylinder, the parking brake piston is forced outward, pushing on the expander piston and the top while the abutment tappet forces the bottom shoe against the drum.

• Upon contact with the drum, the shoes will be forced around, sliding on the abutments in which­ever direction the drum is rotating (Figure 33).

ADJUSTER WHEEL CYLINDER

FORWARD ROTATION

ADJUSTER WHEEL CYLINDER

Thus, regardless of forward or reverse rotation, the brake will always be a two leading shoe brakec

• In the forward direction, the torque load for the top shoe is taken by one piston of the adjuster wheel cylinder bottoming in its bore and the abutmer.t tappet head resting against the ex­pander wheel cylinder body for the bottom shoe.

• In the reverse direction, the torque for the bottom shoe is taken by the other piston of the adjuster wheel cylinder bottoming and the piston head resting against the expander body.

EXPANDER WHEEL

DER

REVERSE ROTATION

EXPANDER WHEEL CYLINDER

Figure 33 - Two Leading Shoe Drum Brake Operation

30

\ }

AIR OVER HYDRAULIC BRAKE SYSTEM

REAR VIEW

LINING INSPECTION HOLE

ADJUSTER SIGHT HOLE

FRONT VIEW

WHEEL CYLINDER/ ADJUSTER ASSEMBLY

WHEEL CYLINDER! PARKING BRAKE EXPANDER ASSEMBLY

Figure 32 - Hydraulic Drum Brake - Front and Rear View - Left Side

• Two single web brake shoes are located by slots in the wheel cylinder tappets and are retained by the shoe return springs. Both shoes are free to slide on their tappet faces and are therefore able to centralize themselves to the drum.

• The brake linings are made of an asbestos-free material and are three-quarters of an inch thick at the center, tapering to approximately five­eighths of an inch at each end.

• The backing plate contains two lining inspection holes, two adjuster sight holes, and two adjust­ment slots. The lining inspection holes allow for

29

inspection and measurement of the lining-to­drum clearance. The adjuster slot allows access to the adjuster wheels on the wheel cylinder I adjuster housing to expand or retract the shoe and lining assemblies. This should only be needed to reset shoes to a specific shoe/ drum clearance during initial installation, or to back off the shoes to enable a lipped drum to be removed.

• The metal backing plate prevents excessive amounts of water and dirt from entering the assembly. The manual adjustment sight holes and lining inspection holes in the backing plate are covered with protective rubber plugs.

I AIR OVER HYDRAULIC BRAKE SYSTEM

Rear Drum Brakes - Automatic Adjustment

• Automatic brake shoe adjustment is carried out only by the adjuster wheel cylinder units; each unit individually adjusts the appropriate shoe. As lining wear increases, the shaft within the ad­juster unscrews to increase the piston length of the adjuster and reduce the shoe-to-drum clearance.

• Each adjuster wheel cylinder piston has an adjuster shaft assembly screwed into it. The rotation of the assembly, relative to the piston, adjusts the brake according to the rate of lining wear (Figure 34).

e When adjustment is required, each brake appli­cation takes up only a percentage of the excess shoe-to-drum clearance. This avoids over-adjust­ment when the drums become hot and expand.

Rear Drum Brakes - Manual Adjustment

• The manual adjustment mechanism has two functions: to set the initial shoe-to-drum clear­ance and to back off the shoes to allow a lipped drum to be removed.

NOTE: The manual adjuster should not be considered as an alternative to the automatic adjuster.

• With automatically adjusted brakes it is impor­tant to set the shoe-to-drum clearance prior to driving the vehicle. This will prevent excessive movement of the wheel cylinder pistons and also ensure that the correct running clearance of the auto-adjuster is quickly achieved and stabilized.

Front Disc Brakes

• Dual piston, pin sliding caliper hydraulic front disc brakes are available as standard equipment on the Cargo vehicle (Figure 35). These brakes are actuated by the air/hydraulic intensifier and are used in conjunction with the hydraulic drum brakes on the rear axle.

31

• The disc brake caliper (Figure 36) is a new pin slider design with dual pistons on the same side· of the rotor. The pistons and cylinder bores are protected by boot seals fitted to a groove in the piston and the caliper housing. The new design allows the caliper to slide on two pins that are integral to the caliper housing and located out­side the torque plate.

PISTON

PISTON LENGTH

t

Figure 34 - Automatic Adjuster Operation

WHEEL HUB -26542·

ROTOR

Figure 35 - Hydraulic Front Disc Brake

AIR OVER HYDRAULIC BRAKE SYSTEM

-2K004-SHIELD

SLIDING PIN

CALIPER

BOOT

-2B121-·2B120-CALIPER

2B540-RH 2B541-LH ADAPTER

-1190-RETAINER

-1201-INNER HUL.LER BEARING

-2B542-ROTOR AND HUB ASSEMBLY

-1216-

PISTON

0UTER ROLLER BEARING

Figure 36 - Hydraulic Front Disc Brake - Exploded View

32

DAMPENING PLATE

AIR OVER HYDRAULIC BRAKE SYSTEM

Air Parking Brake System

Parking Brake Control Vaive

• The parking brake control valve in the Cargo vehicle is a push-pull manually operated air con­trol valve (Figure 37). It is pressure sensitive and will automatically move from the parking brake released position to the apply position if both the primary and secondary air reservoirs are re­duced to below 240-311 kPa (34-45 psi).

• Air pressure is constantly supplied to the supply port from the air reservoir.

• As the control valve is pushed in, air is supplied to the spring brake chambers and the parking brakes are released. This air pressure also acts on the surface area of the inlet and exhaust valve to keep the valve in.

• If the air pressure to the valve is reduced to 240-311 kPa (34-45 psi), the return spring in the brake chamber will overcome the force of the air pressure. The valve will pop out and the park­ing brakes will be applied. Air in the chambers will be released through the quick release valve exhaust.

• The parking brake is applied by pulling out the control valve. This releases air from the cham­bers through the quick release valve.

DELIVERY PORT

DELIVERY PORT

EXHAUST PORT

Part No. 2A622

Figure 37 - Parking Brake Control Valve

33

Quick Release Valve

• The function of the quick release valve is to speed up the exhaust of air from the spring brake chambers. The quick release valve exhausts air quickly enough so that the air cannot travel back to its source; it is released to the atmosphere.

• The line connected to the top port (Figure 38) is the delivery line from the parking brake control valve. The two side ports are for the brake chamber connections and the bottom port is for exhaust.

• When the parking brake control valve is push­ed in, air pressure enters the quick release valve supply port. The diaphragm moves down and seals the exhaust port. At the same time, air pressure forces the edges of the diaphragm down and air flows out the delivery ports to the spring brake chambers.

• When the parking brake control valve is releas­ed, the air pressure above the diaphragm is released back through the quick release valve exhaust. Air pressure beneath the diaphragm forces the diaphragm to rise, opening the exhaust port and allowing the air in the chambers to release to the atmosphere.

Double Check Valve

• The function and operation of the double check valve were covered in the Air System section.

BRAKE CHAMBER PORT

COVER

DIAPHRAGM

BRAKE CHAMBER PORT

•o-RING

Part No. 2A095

Figure 38 - Quick Release Valve

AIR OVER HYDRAULIC BRAKE SYSTEM

Spring Brake System

• A spring brake chamber is installed at each of the rear brakes. The unit consists of the con­ventional air parking brake chamber and a spring loaded pushrod assembly that applies the rear brakes (Figure 39).

• In normal driving (brakes released) the brakes are held in the released position by the air pres­sure. Air reservoir pressure in the air chamber keeps the power spring compressed.

• When the parking brake control valve is opened, the air pressure in the air chamber is released through the quick release valve (Figure 40). This release of air pressure releases the power spring which moves the pushrod forward and forces the wedge and roller assembly between the pistons in the wheel cylinder. The brake shoes are forced apart and the brake is applied (Figure 39).

• In the event it is necessary to move the vehicle after an emergency application (before air pres­sure can be restored), the power spring may be compressed mechanically to release the brake. Instructions may be found in the Service Proce­dures section.

CAGING NUT

POWER SPRING

DIAPHRAGM

BREATHER

QUICK RELEASE VALVE

SPRING BRAKE CHAMBER

Figure 40 - Quick Release Valve and Air Lines

AIR SUPPLY PORT

MOUNTING NUTS (4)

PUSH ROD ASSEMBLY

RN SPRING

Figure 39 - Spring Brake Chamber Sectional View

34

AIR OVER HYDRAULIC BRAKE SYSTEM

RUBBER BOOT

SPRING BRAKE CHAMBER

AIR LINE

CLAMP BAND

Figure 41 - Spring Brake Chamber

SERViCE IP'ROCEDURES

WARNING: When servicing brake systems and components, the following precautions should be observed:

1. Always block the wheels of the vehicle before servicing.

2. Keep hands away from the parking brake chambers; they may apply if system pressure drops.

3. Never connect or disconnect a hose contain­ing pressure; it may whip. Never remove a component or plug unless you are certain that all system pressure is depleted.

4. Never attempt to disassemble a component unless you have read and understand all recommended procedures. Some components contain powerful springs and injury can result if they are not properly disassembled.

5. Use only Ford approved replacement parts and components.

35

Compressor

• It is important that the compressor receives a clean supply of air. The engine air filter must be kept clean and be properly serviced.

• The compressor intake is connected to the engine air cleaner. These connections must be proper­ly installed, tightened, and maintained.

• Check compressor mounting bracket to be sure it is tight.

• Be sure the drive pulleys are in proper alignment and belt tension is properly adjusted.

• Inspect the oil supply and return lines. Be sure these lines are properly installed and that the compressor is getting the proper supply of oil; just as important, be sure that the oil is return­ing to the engine. Check the coolant lines to and from the compressor and see that the cooling fins on the crankcase are not clogged with dirt, grease, etc. Check the unloader mechanism for proper and prompt operation.

• Air leakage past the discharge valves can he detected by removing the discharge line, apply­ing shop air back through the discharge port, and listening for escaping air.

• The unloader piston can be checked for leakage by building up the air system until the governor cuts out, then stopping the engine. With the engine stopped, listen for escaping air at the air compressor intake. To pinpoint the leakage, apply a small amount of oil around the unloader piston. No leakage is permitted. If the compres­sor is not functioning as described or leakage is excessive, it is recommended that it be replaced.

AIR OVER HYDRAULIC BRAKE SYSTEM

Governor

Operating Tests

• Start the engine and build up air pressure in the system. With a dash or test gauge, measure the pressure in the system at the time the governor cuts out. This is the compressor cut-out pressure.

The compressor cut-out pressure should be between 793-862 kPa (115-125 psi) if the test gauge is used.

If the dash gauge is used, the pressure should range between 752-903 kPa (109-131 psi), allowing for dash gauge accuracy.

• With the engine still running, make a series of brake applications to reduce the air pressure and observe at what pressure the governor cuts in the compressor. This is the compressor cut-in pressure.

Compressor cut-in pressure should be at 620-772 kPa (90-112 psi), or 89-172 kPa (13-25 psi) below the cut-out pressure.

• If the governor does not control the compressor in accordance with these specifications, allow­ing for gauge accuracy, the governor should be replaced.

Leakage Tests

• Leakage checks on the governor are made at its exhaust port in both cut-in and cut-out positions. In the cut-in position, check the exhaust port for inlet valve leakage by applying a soap solution at the port. Leakage could also be past the bot­tom piston grommet. In the cut-out position, check the exhaust port to determine leakage at the exhaust valve seat or stem grommet. In this position leakage could also be past the upper piston grommet.

36

• Leakage in excess of a 25mm (1 inch) soap bub­ble in three seconds is not permissible in either of the foregoing tests. If excess leakage is found, the governor must be replaced.

Reservoirs

• If the air supply system is not properly main­tained for its operating conditions, then the system can become filled with moisture and other contaminants which can cause damage to the brake system internal components ( dia­phragms, valve seats, seals, etc.). Daily drain­ing of the air reservoir to 0 kPa (0 psi) is very important to ensure trouble-free brake system performance. More frequent maintenance is re­quired in dusty or high humidity environments.

Air/Hydraulic Intensifier

• Maintain hydraulic fluid within 6.35mm (114 inch) of the top of the reservoir. Use Ford approved brake ~uid or equivalent when filling the reserv01r.

• Each month, 8000 miles or 300 operating hours:

- Check the tightness of the mounting nuts.

- Inspect the hydraulic and air line fittings for tightness.

- Refill the reservoir to the proper level if the fluid level is low.

• Each year, 200,000 miles or 3,SOO operating hours:·

- Disassemble the intensifier chamber and clean all parts. Replace the diaphragm, reser­voir gasket, seals and any other parts that are worn or damaged.

AIR OVER HYDRAULIC BRAKE SYSTEM

To Test for Air Leaks

• Apply brakes with normal air pressure and hold. Coat the chamber with soapsuds and check for leaks. If the chamber leaks, replace the dia­phragm. Also check for air leaks at all fittings, drain holes, and the clamp ring of the brake chamber.

To Check Master Cylinder leakage

• System pressure should be at least 620 kPa (90 psi).

• Make a full brake application, hold for 5-10 seconds, and release.

• Check for fluid leaks at all fitting connections.

Hydraulic Drum Brakes -Manual Adjustment

• With automatically adjusted brakes it is impor­tant to set the shoe-to-drum clearance prior to driving the vehicle. This will prevent excessive movement of the wheel cylinder pistons and also ensure that the correct running clearance of the auto-adjuster is quickly achieved and stabilized.

• To set the initial shoe-to-drum clearance, follow these procedures:

1 . Remove the rubber plugs from the adjuster sight hole and lining inspection holes on the backing plate.

2. Insert the adjusting tool or a suitable blunt screwdriver and engage a slot in the manual adjustment wheel (Figure 42). Using the backing plate as a fulcrum, rotate the wheel counterclockwise until the shoe-to-drum clearance is less than l.Smm (0.070 in.).

3. Apply and release the service brake to cen­tralize the shoes.

37

4. Insert a feeler gauge and check each shoe­to-drum. clearance (Figure 43). If the clear­ance is not 0.51 to 0.76mm (0.020 to 0.030 in.), manually rotate the adjustment wheel to obtain the specified dimensions.

5. Reinstall the rubber plugs.

RUBBER PLUG

MANUAL ADJUSTMENT WHEEL

Figure 42 - Manual Brake Adjustment

BRAKE BACKING PLATE

RUBBER ACCESS PLUG

Figure 43 - Shoe-to-Drum Clearance Check

AIR OVER HYDRAULIC BRAKE SYSTEM

• To back off the shoes in order to remove a lipped brake drum, follow the procedures above but rotate the adjustment wheel clockwise until the lining clears the drum, as viewed through the inpection hole (Figure 44). Repeat this procedure with the other shoe to remove the drum.

Hydraulic Disc Brakes

• Replace the brake lining pad assemblies when the lining is worn to a minimum thickness of 0.794mm (.032 inch) above the pad backing plate. Always replace the brake lining pads on both sides of the vehicle. Failure to do so will result in uneven braking pressures.

NOTE: The absence of the lining grooves in the brake pad indicates that the lining has reached a worn out condition.

Brake Pad Replacement

• Replacing the brake pads on the Cargo front disc brakes is a simple procedure.

1. Remove approximately two-thirds of the total brake :fluid from the front brake master cylin­der. Do not drain the reservoir completely.

2. Raise the vehicle evenly and support it on a jack or safety stands. Remove the front wheel and tire assembly or the rim and tire assembly.

3. Remove the two retaining bolts that attach

LINING INSPECTION PLUG

F1gure 44 - Pulling Back Brake Shoes to Remove Lipped Drum

38

the dampening plate to the caliper. Remove the dampening plate.

4. The brake pads may simply be lifted out of the caliper and replaced with new ones. Use a piece of 2 x 4 and a C clamp to compress the pistons before inserting new pads.

Spring Brake Chamber

Manual Brake Release

• The spring brake chamber is equipped with a manual spring release. Releasing the brakes manually may be necessary in the following circumstances:

- A malfunction in the air supply or parking brake air circuit prevents normal operation of the brake when the vehicle must be moved or the brakes must be serviced.

- The vehicle must be towed.

- The vehicle must be readied for long term storage.

• To release the parking brake manually, follow these procedures:

1. Remove the rubber boot at the end of the chamber.

2. Turn the return screw counter-clockwise until resistance is felt.

3. Turn the caging nut outside the screw clockwise until return screw bolt is fully extended (Figure 45).

~--.,_...,_ SPRING BRAKE CHAMBER

CAGING NUT RETURN SCREW

Figure 45 - Manual Brake Release

AIR OVER HYDRAULIC BRAKE SYSTEM

WARNING: The brake chamber is spring loaded and the power spring must be caged before per­forming any service procedures. To cage the power spring, follow the previous procedures for manual release of the brake.

Chamber Removal

• To remove the spring brake chamber from the vehicle follow these procedures:

1. Release all the air from the system and disconnect the air lines from the brake chamber.

2. Manually cage (compress) the parking brake spring according to the procedures above.

3. Remove the 4 mounting nuts and remove the brake chamber.

39

Chamber Installation

1. Position the brake chamber assembly on the mounting bracket and install the attaching nuts.

2. Connect the air lines to the brake chamber and build up the air pressure.

3. Reset the parking brake by returning the caging screw to its original position.

• Brake chamber diaphragms should be replaced every 50,000 miles (80,467 km) or 12 months. They should also be replaced whenever the brake chamber is leaking or has been serviced.

DIAGNOSIS

• For diagnostic charts and procedures, refer to the Shop Manual.

SUSPENSION SYSTEM

DESCRIPTION

• Semi-elliptic, leaf-type front and rear springs are used on the Cargo vehicle. The springs are mounted to the axles and secured by U-bolts.

• The shackle bracket has a new longer life tandem bushing. Instead of one bushing, the bracket now has two bushings with space between them for lubricating material.

·5340· MOUNTING BRACKET

·5494· STABILIZER BAR

·3010· AXLE

• The front suspension of the Cargo truck will have longer springs and a stabilizer bar to pro­vide balanced, level turning (Figure 46).

• The rear suspension spring (Figure 4 7) is much like the current rear suspensions except it can be equipped with a stabilizer bar assembly (Figure 48).

·18045· SHOCK ABSORBER

·5335· SHACKLE BRACKET

·5310· SPRING ASSEMBLY

Figure 46 - Front Suspension with Stabilizer Bar and Shock Absorber

40

[

-5W482-LH -5L499-RH STABILIZER BAR BRACKET

SUSPENSION SYSTEM

-5588-UPPER SPRING ASSEMBLY

·5560·

-5993-MOUNTING BRACKET

LOWER SPRING ASSEMBLY

-5789-SPRING SEAT

-5786-AXLE CAP

Figure 47 - Rear Suspension

-5A772· STABILIZER BAR

-5786-AXLE CAP

Figure 48 - Rear Suspension with Stabilizer Bar and Shock Absorbers

41

FRONT AXLE

DESCRIPTION

• 9,000 lbs. and 12,000 lbs. front axles are standard on the Cargo 6000 and 7000 models, respectively. The axle on the Cargo vehicle is the same as that used presently on the 1-Series truck.

• The location of the steering arm is different on the 9,000 and 12,000 lbs. axles. The steering arm is in the front spindle quadrant of the 9,000 lbs. axle (Fignre 49). With the 12,000 lbs. axle, the steering arm is in the rear quadrant (Fignre 50).

• For more information and service procedures refer to the Shop Manual.

·3130· SPINDLE ARM -3280-

SPINDLE CONNECTING ROD

CONNECTING ROD BALL STUD HOUSINGS (ROD END) SHOULD BE PARALLEL TO EACH OTHER AND IN THE SAME PLANE WITHIN s•

END CLAMP TIGHTEN TO 68·95 N·m (50·70 ft. lb.) AFTER ADJUSTING TOE·IN

·3113· /SPINDLE CAP

·3114· GASKET

·3146· STEERING ARM

·3115· SPINDLE PIN

SPINDLE

·3010· FRONT AXLE

CONNECTING ROD END BALL STUD

-3105-SPINDLE

~FRONT OF ~ VEHICLE

Figure 49 - Front Axle with Steering Linkage - 9,000 lb. Capacity

42

FRONT AXLE

CONNECTING ROD BALL STUD HOUSING (ROD END) SHOULD BE PARALLEL TO EACH OTHER AND IN THE SAME PLANE WITHIN 5°

END CLAMP TIGHTEN TO 68-95 N·m (50-70 ft. lb.) AFTER ADJUSTING TOE-IN

'i If

-3113· .-Y":~k SPINDLE CAP ----<>;> S -3114-J:.jgl GASKET ----------~~

~ 1 I -3115· SPINDLE PIN -----.,._!

SPINDLE

-3010· FRONT AXLE

-3131-LH -3130-RH SPINDLE ARM

-3146· STEERING ARM

FRONT OF VEHICLE

Figure 50 - Front Axle with Steering Linkage - 12,000 lb. Capacity

43

CAB TILT MECHANISM

DESCRIPTION

• The cab latch mechanism on the Cargo vehicle features a key-like operating handle that Jocks and unlocks the latch assembly. This handle is separate from the assembly and is kept inside the cab.

• The operating handle fits into the cab tilt lock located on the back of the cab on the right hand side (Figure 51). The handle releases the lock and allows the cab to be tilted.

·11523·

• The cab Jock assembly latches onto a striker pin installed on the cab mounting posts. The cab mounting posts are attached to the frame cross­members on each side of the vehicle.

• The cab latch mechanism is equipped with a cab latch warning switch mounted on the rear of the cab. Its function is to activate a warning light on the instrument panel when the cab is not securely locked down.

ROD CAB LOCK WARNING SWITCH CAB TILT -5L384-

TILT LOCK REAR OF CAB

·5L369-STRIKER PIN

Figure 51 - Cab Tilt Mechanism

44

LOCK ASSEMBLY

CAB RELEASE LEVER

FRONT OF VEHICLE

CAB TilT MECHANISM

OPERATION

Cab Tilting

1. Apply the parking brake or block the wheels. Ensure the gear lever is in the NEUTRAL position. Ensure that all items in the cab are secure, the doors are closed, and the mirrors are folded flat to the doors.

2. Insert the cab tilt lock handle into the lock and turn it counter-clockwise approximately 45 o to engage the lock.

3. Press the cab release lever and pull out the cab tilt lock handle to expose the orange lock indicator. The cab is now unlocked.

4. Tilt the cab up and forward to about a 40° angle position.

• At this point the cab stay assembly is fully extended and supporting the cab (Figure 52): Push the cab stay forward to an _over center _POSI­tion. The cab will lower approximately .88 mch.

• The cab may also be tilted further to a 50° angle. This is achieved by removing the lower mount-

CAB STAY

50° ANGLE POSITION

ing bracket screw at the base of the stay assem­bly. This allows the cab assembly to be extended to its furthest limit for improved accessability to the engine.

Cab Lowering

1. Ensure that the gear lever is in the NEUTRAL position.

2. Raise the cab from the rear about 20 mm and pull the cab stay rearward from the cen­tral pivot.

3. Lower the cab and slam it shut. (The orange lock indicator when retracted into the lock in­dicates that the cab is fully locked.)

4. Switch on the ignition to check if the cab latch warning light comes on.

5. Realign the rear view mirrors.

WARNING: Do not operate the vehicle if the cab latch warning lamp is on or the orange lock retractor is not retracted.

I I ~-~ ~- ~~ r

CAB

MOUNTING BRACKET

Figure 52 - Cab Stay Assembly

45

ov·-

CAB TILT MECHANISM

SERVICE PROCEDURES

Cab Locking Adjustment

• To adjust the cab locking mechanism follow these procedures:

1. Ensure that both Jock mechanisms (regular lock assembly and safety hook) are engaged and that the lock position indicator is fully retracted.

2. Push the cross rod toward the right hand side of the vehicle until it stops.

REAR OF CAB

-56374-CROSS ROD

-11523-CAB LOCK WARNING SWITCH

I ~

-5L382-CAB LATCH ASSEMBLY

3. While holding the cross rod in this position, turn the vertical lever adjuster screw until it contacts the left hand side of the vertical lever (Figure· 53A). (The screw may be screwed either in or out, depending upon its original position.)

4. Back off the adjuster screw a half turn.

5. Repeat this procedure with the other vertical lever adjuster screw.

6. Check to make sure the cab tilts properly.

-5A377-ACTUATING ROD

VERTICAL LEVER ADJUSTER SCREW

-5L384-TILT LOCK (OPERATING) HANDLE

FRONT OF VEHICLE

Figure 53 - Cab Lock Adjustment

46

5mSPEED TRANSMISSION

DESCRIPTION

• The Cargo vehicle is equipped with a Clark 5-Speed transmission (Figure 54). Detailed infor­mation and service procedures regarding this feature will be .covered in a separate publication.

Figure 54 - Clark 5-Speecl Transmission

SHIFT LEVER

\ SHIFT LEVER BRACKET

SERVICE PROCEDURES

linkage Adjustment

• The following new procedures should be follow­ed when adjusting the transmission linkage.

1. Shift the transmission into the NEUTRAL position.

2. Lock the shift lever in position by inserting a lock pin through the holes in the fork and into the gear lever bracket (Figure 55).

3. Check the dimensions of the lower ball joint and control rod. Adjust to the dimensions shown, if necessary (Figure 55).

4. After adjustment, remove the pin and check that all gears mesh correctly.

• For transmission alignment procedures, see Clutch Installation and Transmission Installation in the Shop Manual.

78·80 mm (3.07-3.15 in.)

LOWER BALL JOINT

CONTROL ROD

Figure 55 - Transmission Linkage Adjustment Specifications

47

WHEEL NUTS

DESCRIPTION

• The disc-type wheels are attached to the studs on the brake drum by eight or ten nuts with a metric thread (M 20 for 8-hole wheels, M 22 for 10-hole wheels). The nuts have a right hand thread and an integral washer.

• The wheel is piloted on the hub at four locations surrounding the hub.

INNER WHEEL

OUTER WHEEL

Figure 56 - Wheel Assembly with New Wheel Nut

COOLING SYSTEM

DESCRIPTION

• Cooling of the engine is accomplished by passing coolant through the radiator. The radiator con­sists of an upper and lower header tank and an inter-connecting "tube and fin" type cooling core.

• The radiator outlet port (lower header tank) is connected to the water pump inlet port (Figure 57). The radiator inlet port (upper header tank) is connected to the coolant outlet elbow of the engine; this allows for coolant circulation through the radiator when the thermostat is open.

System Venting

• Aeration of the cooling system is prevented by a set of vent lines and the placement of the coolant supply tank.

48

NOTE: A deaeration system is needed because the radiator is placed on a plane that is beneath the plane of the engine. Without a deaeration system, air bubbles forming in the system would gather in the engine. Air bubbles can cause hot spots in the engine which result in engine damage.

• The cooling system has two aeration points: one in the engine (at the thermostat housing) and the other on the upper tank of the radiator. Air that is removed from the system goes to the coolant supply tank, which is the point of coolant fill. Air in the cooling system is displaced by coolant drawn from the supply tank through the engine make-up line.

COOLING SYSTEM

Coolant Supply Tank

o The coolant supply tank provides a constant supply of deaerated coolant to the system through the make-up line. It is mounted behind the cab on the right hand side.

• The supply tank outlet is connected to the water pump inlet tube by the make-up line.

• The filler neck on the supply tank prevents over­filling of the system and is covered with a seal­ing cap. The pressure cap is installed on top of the supply tank and incorporates a pressure and vacuum relief valve. The pressure cap should not usually be removed as filling of the system is normally done at the filler neck.

Viscous Fan Clutch

• A thermally controlled viscous fan clutch is directly driven by the crankshaft and operates the engine cooling fan.

• Air temperature behind the radiator is sensed by a bimetallic coil located in the center of the fan clutch face. When a predetermined temperature is reached, the coil opens a valve within the clutch. The valve allows a viscous liquid to pass from an integral reservoir to the drive area.

RADIATOR VENT LINE

• Within the drive area are two sets of interlock­ing annular (ring shaped) fins. One set is on the drive member and the other set is on the freewheeling hub body, which the fan assembly is attached to. Fluid passes between the inter­locking blades and the resulting drag transmits torque to the fan. The fluid is then recirculated to the reservoir by a pump plate in the drive member.

• When the air temperature behind the radiator drops sufficiently, the bimetallic coil closes the valve. Fluid is prevented from entering the drive area and the fan hub is allowed to idle with respect to the drive member.

Engine Oil and Transmission Fluid Coolers

• The radiator is equipped with two in-tank coolers: one for the transmission fluid and one for the engine oil.

• Fluid lines from the transmission and the engine feed into the cooler reservoirs at the bottom of the radiator and the fluids are cooled by the radiator.

• The engine oil cooler line connects to the engine near the oil filter. Cooled engine oil is returned to the engine at the oil pan.

COOLANT SUPPLY TANK -- PRESSURE CAP

~ \ ENGINE ~ENT LINE (\ ~ THERMOSTAT HOUSING ~

fll FILLER - 0 CAP

ENGINE

RADIATOR__.,.-ENGINE

A~ MAKE·UP LINE

/7 OIL COOLERS

Ji 11P (2) II II _,;?ENGINE OIL COOLER LINES

Figure 57 - Cooling System

49

CHARGING SYSTEM

DESCRIPTION

• The charging system is made up of several mechanical and electrical components that work together to provide electricity for the vehicle's electrical system. The charging system basically performs the following functions:

1. The charging system generates the power to operate all the electrical components in the vehicle when the engine is running.

2. The system charges the battery.

• The components making up the charging system are:

Alternator Drive belt Regulator Starter Relay Ignition switch Battery Cables and wiring harness

FIELD TERMINAL

GROUND

Alternator

• The alternator is an alternating current (AC) generator that produces electricity for the electrical system and recharges the battery when required. A rectifier is built into the alternator to change the generated current from ACto DC, which the vehicle uses.

• The alternator will be available in 60 and 75 ampere ratings (Figure 58).

Drive Belt

• The drive belt spins the rotor shaft in the alter­nator when the engine is running. 'fhe belt is driven from the crankshaft pulley. Drive belt tension should be checked periodically to assure proper operation of the alternator and charging system. A loose drive belt can inhibit charging. A belt that is too tight, however, can lead to early bearing failure.

STATOR TERMINAL

DRIVE BELT

BATTERY TERMINAL

Figure 58 - Alternator with Connections

50

CHARGING SYSTEM

Regulator

• The voltage regulator controls the output voltage of the alternator by varying alternator field voltage to meet system demands.

• When battery voltage is low and the electrical accessory load is high, the regulator will increase the alternator current output to recharge the battery - or, in the case of a heavy electrical load, the regulator will permit accessory opera­tion with little drain on the battery; most of the current will come directly from the alternator. Likewise, when the battery is fully charged and accessory load is low, alternator current output is reduced.

Ignition Switch

• The ignition switch closes the circuit which supplies the power to operate the indicator light and stimulate the alternator field.

Starter Relay

• The starter relay provides a junction or electrical connection between the battery and the starter motor.

Battery

• All Cargo vehicles are equipped with two 12-volt batteries connected in parallel and mounted on a support on the vehicle's right side member. The battery in the Cargo vehicle is a low maintenance type and should be checked for electrolyte level yearly.

Cables and Wiring Harness

• These connect all the system components and conduct electricity throughout the vehicle.

FRONT HOUSING

PULLEY FAN

ROTOR

=

~ ~@@ ~ @ ~ ~- /'\t.,@Y' 'A\1'<.

IJ-;;J~ ' FRONT BEARING

RECTIFIER

BRUSHES

®!@@@@@

®!@®®®® @@®@@

REAR HOUSING

Figure 59 - WAPSA 60 Amp Alternator

51

STATOR

CHARGING SYSTEM I OPERATION

• The alternator is belt driven from the engine. Field current is supplied from the alternator regulator to the rotating field of the alternator through two brushes and two slip rings (Figure 60).

• The alternator produces power in the form of alternating current. The alternating current is rectified to direct current by six diodes. The alternator regulator automatically adjusts the alternator field current to maintain the alter­nator output voltage within prescribed limits to correctly charge the battery. The alternator is self current limiting.

• Three fuse links are included in the charging system wiring on all models. Two fuse links are located at the starter motor battery terminal. One is located at the alternator battery terminal. Fuse links are used to prevent damage to the wiring harness if the wiring harness should become grounded.

BATTERY TERMINAL OF STARTER MOTOR

SERVICE PROCEDURES

• If the alternator needs replacing, it may be replaced with a Motorcraft alternator with the same ampere rating.

• The regulator in this system is 100 percent solid state. If it is damaged or malfunctioning it must be replaced with the equivalent Motorcraft volt­age regulator.

• Check the alternator drive belt tension period­ically using a belt tension gauge, Tool No. T63L-8620-A or equivalent.

Specifications

Rating Field Current Amperes @ 15V Watts@ 15V Amps@ 12V

60

75

ALTERNATOR WARNING& INDICATOR LIGHT

900 4.25

1125 4.00

~TO BATTERY ,-· I HOT

IN RUN ..c-=tl- --1 ~o-.-----...... ":' BATTERY FUSE LINKS

-,--, IGNITION I SWITCH

ALTERNATOR OUTPUT--..... TERMINAL (BAn

DIODE RECTIFIER

ALTERNATOR ,.-;----

'

SLIP RINGS

FUSE LINK

AMMETER

STA--- STATOR TERMINAL

FIELD TERMINAL

A

s

F

I I I

I I L

Figure 60 - Alternator Charging System

52

ELECTRONIC VOLTAGE REGULATOR

I I I I I I I I I

______ j

CHARGING SYSTEM

ON VEHICLE DIAGNOSIS

CONDITION POSSIBLE CAUSE RESOLUTION

Battery does not 1. Battery 1. Test battery; replace if necessary (2). stay charged - engine

2. Loose or worn alternator belt 2. Adjust or replace belt (1). starts OK

3. Damaged or worn wiring or cables 3. Service as required.

4. Alternator 4. Test and/or replace components as required (3).

5. Regulator 5. Test; replace if necessary (4).

6. Other vehicle electrical systems 6. Check other systems for current draw. Service as required (1).

Alternator noisy 1. Loose or worn alternator belt 1. Adjust tension or replace belt (1).

2. Bent pulley flanges 2. Replace pulley (3).

3. Alternator 3. Service or replace alternator (3).

Lamps and/or fuses burn 1. Damaged or worn wiring 1. Service as required (1). out frequently 2. Alternator regulator 2. Test, service, replace if necessary (4).

3. Battery 3. Test, replace if necessary.

Battery is overcharging 1. Defective regulator 1. Test; replace if necessary (4).

2. Loose ground wire between regulator 2. Service as required. and alternator

3. Battery 3. Test battery; replace if necessary (3).

Charge indicator gauge 1. Loose or worn alternator belt 1. Adjust tension or replace belt (1). shows discharge

2. Damaged or worn wiring (battery to 2. Service or replace wiring. alternator for ground or open)

3. Field circuit ground 3. Repair or replace wiring.

4. Alternator 4. Service or replace (3).

5. Regulator 5. Test, replace if necessary (4).

6. Charge indicator gauge wiring and 6. Service as required (1 ). connections

7. Damaged or worn gauge 7. Replace gauge (1).

8. Other vehicle electrical system 8. Service as required. malfunction

(1) Refer to Charging System General Service Section (Section 31-01) of the Shop Manual. (2) Refer to Battery Section (Section 31 -02) of the Shop Manual. (3) Refer to Appropriate Alternator Section of the Shop Manual. (4) Refer to Alternator Electronic Regulator Section (Section 31-43) of the Shop Manual.

53

ELECTRICAL SYSTEM AND WIRING CONNECTORS

DESCRIPTION

• The Cargo wiring system is basically made up of 4 main wiring assemblies.

14401 14398

15A404

14405

For an explanation of these wiring assemblies and the components that are connected to them, consult the Shop Manual or Truck Wiring and Vacuum Diagrams.

• Because the Cargo is derived from a European vehicle, the wiring system may be somewhat different from other vehicles serviced. For example:

- The color codings for the wiring system are completely different from other Ford Trucks.

Most of the connectors are new to North America and will be substantially different in design and configuration.

- The routing of the wiring assemblies through the vehicle may be unlike that of other Ford vehicles.

• The following factors should be considered when servicing the Cargo vehicle electrical system:

- Although the Cargo electrical system is unique from other Ford trucks, the base part numbers for the connectors, wiring assem­blies, and .fuse links have remained un­changed. Of course, if a new connector, wiring assembly, or fuse link has been added to the system then it will have a new part number (prefix and suffix). Refer to the Shop Manual or Truck Wiring and Vacuum Diagrams for more detailed information and service part numbers.

- Because most of the connectors are unique to the Cargo vehicle, a stock connector may not be used as a replacement. The replace­ment connector must be a unique Cargo connector or both the male and female con­nectors must be replaced with new ones.

54

Starter

• The Cargo vehicle is equipped with a new 12-volt Delco Remy heavy duty starter. This starter is a 37 MT series, type 300. For details on the new starter, refer to the Shop Manual.

Fuse Module

• Circuit protection is provided by a fuse module located under the dash panel on the passenger side (Figure 61). This unit houses all of the fuses and relays for the vehicle. The module holds 21 blade-type fuses, up to 4 spare fuses, the turn signal flasher, air pressure buzzer, up to 5 circuit breakers, and 5 relays.

• To remove the fuse module cover, simply turn the two thumb screws and lift the cover away from the dash panel.

Diagnosis and Service Procedures

• Refer to the Shop Manual or Truck Wiring and Vacuum Diagrams for information on diagnosis and service procedures.

FUSE LEGEND

RELAYS

FUSE MODULE COVER

Figure 61 - Fuse Module

STEERING COLUMN SWITCHES

DESCRIPTION

• There are three switches located on the steer­ing column (Figure 62).

- Combined turn indicator/horn and headlamp flash switch

- Windshield wiper/washer switch

Ignition switch with steering lock

• All three switches are fitted to a common mount­ing bracket attached to the steering column.

Tum !ru::licator/Hom and Headlamp Flash Switch

• The turn indicator switch is located on the left hand side of the steering column and it controls the turn indicator lights on the front and rear of the vehicle. The lights are illuminated via a flasher unit which causes them to flash between 60 and 120 times per minute. Green right and left indicator lamps on the instrument panel flash simultaneously with the outside indicator lights when the switch is actuated.

• When it is operated, the direction indicator switch self cancels as the steering is returned to the straight ahead position. This is achieved by a cancelling collar, which forms part of the switch, fitted over the steering column and re­tained by a spring clip.

TURN INDICATOR/HORN AND HEADLAMP FLASH SWITCH

WINDSHIELD WIPER/ WASHER SWITCH

• The horn is actuated by pushing in on the end of the turn indicator stalk.

• The headlamp dimmer switch is a three-position switch controlled by moving the turn indicator stalk closer to or farther from the plane of the steering wheel. The positions are: MOMEN­TARY HIGH BEAM, LOW BEAM, and HIGH BEAM in order of increasing distance from the plane of the steering wheel.

Windshield Wiper/Washer Switch

• The wipers are actuated by a four-position switch that regulates the speed of the wipers (INTER­MITTENT, OFF, SLOW, FAST). This switch is located on the right side of the steering column. The switch also actuates the washer pump.

Ignition Switch with Steering lock

• The ignition switch is equipped with a steering lock mechanism which operates when the key is removed. When the ignition switch is moved to the OFF position and the key is removed, a spring loaded locking element is actuated in the steering shaft, thus preventing rotation of the steering wheel.

Figure 62 - Steering Column Switches

55

STEERING COLUMN SWITCHES

SERVICE PROCEDURES

• All three switches are mounted on the steering column (Figure 63) and serviced by removing the upper right hand and left hand steering column shrouds and the steering wheel. To remove the steering column shrouds:

1. Position the vehicle so that the wheels are in the straight ahead position.

2. Apply the parking brake and disconnect the battery.

3. Remove the steering wheel center cap.

NOTE: If there is not an arrow scribed on the steering shaft, scribe an arrow in the straight ahead position to ensure correct positioning of the steering wheel when replacing it.

4. Unscrew the steering wheel retaining nut and remove the steering wheel.

5. Remove the shroud screws, separate the shrouds and remove.

Wiper Switch Removal and Installation

Removal - Refer to Figure 63

1. Unplug the multiplug from the switch mounting.

2. Remove the securing screws and ease the switch away from its mounting.

3. Remove the switch multiplug connector from its location, then remove the switch with its plug.

Installation

1. Position the switch multiplug connector into its location on the mounting plate. Position the switch and secure it with retaining screws.

2. Reconnect the multiplug.

MULTIPLUG CONNECTOR TURN INDICATOR/HORN AND HEADLAMP FLASH SWITCH

WINDSHIELD WIPER/WASHER SWITCH

MULTIPLUG CONNECTOR

SWITCH MULTIPLUG

Figure 63 - Steering Column Switch Connections

56

STEERING COLUMN SWITCHES

Turn Indicator Switch Removal and Installation

Removal - Refer to Figure 63

1. Unplug the multiplug from the switch mounting.

NOTE: Ensure that the switch is in the neutral and regular beam position and that these posi­tions are not moved during removal.

2. Remove the attaching screws (one is accessi­ble from the underside of the mounting). Ease the switch away from its mounting.

3. Remove the multiplug connector from its location, then remove the switch with its plug.

4. If the self-cancelling collar was not removed with the switch, remove it from the steering shaft.

I nstaliation

1. Position the switch over the steering shaft and fit the switch multiplug connector into its location on the mounting plate.

2. Ensure that the self-cancelling collar is in the correct position to locate in the shaft recess. Lower the switch into position and secure with screws.

3. Reconnect the multiplug.

Ignition Switch Removal and Installation

Removal

1. Unplug the multiplug. Remove the switch assembly retaining screw and withdraw the switch from the lock housing.

57

2. To remove the steering lock, drill out the retaining bolts with a 10 mm drill (Figure 64).

Installation

1. Position the switch housing and loosely fit the retaining bolts.

2. Engage the lock plunger with the steering shaft and progressively tighten the bolts. Make sure the plunger is free to move.

3. Tighten the special retaining bolts until their heads break off.

4. Reconnect the multiplug.

• For complete service procedures and diagnostics refer to the Shop Manual.

Figure 64 - Ignition Switch Removal and Installation

HEATING AND VENTILATION SYSTEM

DESCRIPTION AND FEATURES

• The heating and ventilation system in the Cargo vehicle includes a coolant metering heater unit, control panel, and various foot level, face level, and windshield vents (Figure 65).

Heater Unit

• The heater unit is mounted below the central switch panel.

• The coolant metering system is unique to the Cargo vehicle. In the coolant metering system, the temperature of the heated air is controlled by the amount of coolant allowed to circulate through the heater core. As outside air is direct­ed through the core by the blower, the air is heated according to the temperature of the core.

• If more coolant is allowed to circulate in the heater core, the air will be warmer. If less cool­ant is allowed, the air is cooler.

• The flow of coolant through the heater core is controlled by a mixing or metering valve located

FLOOR VENT

at the front of the heater assembly (Figure 66). This valve is cable operated from the tempera­ture control switch on the control panel. The valve opens and shuts to modulate the flow of coolant from the heater core.

- BLOWER ____ LLQV_ INLET -- OUTLET ' ASSEMBLY HOSE HOSE

Figure 66 - Blower Assembly and Valve

·18B539· HEATER CORE

HEATER UNIT

Figure 65 - Heating and Ventilation System

58

HEATING AND VENTILATION SYSTEM

Control Assembly

• The system is controlled by two levers which determine air flow direction and temperature (Figure 67). The Function Selector lever is con­nected to a cable that controls the heat/ defrost door in the plenum. The Temperature Control lever controls the metering valve that regulates the flow of coolant through the heater core.

• The air flow system has a two-speed motor that operates the double blower assembly. The blower motor is controlled by a switch located just below the temperature control panel (Figure 67).

FUNCTION SELECTOR LEVER

BLOWER --L----- TEMPERATURE SWITCH LEVER

Figure 67 - Control Assembly

LATERAL DIRECTION SIDE VENT

FOOT LEVEL VENTS

Vent Assembly

• Air from the system is circulated throughout the cab by means of several vents located in the following areas (Figure 68):

- Two foot-level vents located on each side of the heater assembly below the dash panel.

- Four windshield vents located at the base of the windshield.

Two adjustable face level vents located on each side of the control panel (for ventilation only).

- 'IWo lateral direction vents located in the entry assist handles on each side of the dash panel.

• There are three additional vents located in the cab. They are:

- Roof mounted ventilator located in the roof of the cab.

- Two foot-controlled, foot-level fresh air vents located in the firewall of the cab.

ROOF VENTILATOR

WINDSHIELD VENTS

FOOT CONTROLLED FOOT VENT

Figure 68 - Ventilating Air Distribution

59

HEATING AND VENTILATION SYSTEM

OPERATION

Heating System

• The heater system (Figure 69) receives outside air from the cowl top grille for system operation. Outside air enters the blower from the cowl air intake and is forced through the heater core and into the plenum. Air is then directed to the several vents depending on the position of the Function Selector lever.

• The coolant metering heater produces heat by passing engine coolant through the heater core. As air passes through the heater core, it is heated and then directed into the plenum where it is distributed to the vents.

DISTRIBUTION COVER

·18A584· HEATER CASE

MOTOR LEAD ASSEMBLY

CONTROL ASSEMBLY

Ventilation System

• The ventilation system is operated by ram air from the forward motion of the vehicle.

• When the control assembly is in the vent mode, fresh air is forced through the plenum by the blower and distributed to the various vents.

·18B539· HEATER CORE

MOTOR COVER

FAN COWL

Figure 69 - Heater Assembly

60

HEATING AND VENTilATION SYSTEM

SERVICE PROCEDURES

Blower Check

• Check to see that all blower motor connections are correct including proper ground of the blower motor. Check the resistor connection at the heater case and the heater fuse. Also check the connection at the control head.

• Check the operation of the side vent doors and ensure that they open and close properly. Check for cracked or broken doors, misaligned, kinked, or missing seal. Check the air inlet ducts for restrictions.

Temperature Control Cable Adjustment

1. Set the temperature control lever approx­imately 2 mm (.08 in.) from the COLD posi­tion on the control panel (Figure 70).

2. Set the heater outlet valve to the position illustrated. There should be about 10 to 15 mm (.4-.6 in.) of exposed cable between the cable retaining clip and the valve lever.

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I

TEMPERATURE CONTROL LEVER

2 mm (.08 in.)

Figure 70- Temperature Control Cable Adjustment

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HEATING AND VENTILATION SYSTEM

DIAGNOSIS

CONDITION POSSIBLE CAUSE RESOLUTION

Insufficient, erratic or no 1. Engine coolant level too low. 1. Check and refill, if necessary. heat or defrost. 2. Blower switch. 2. Check blower switch operation through

all speeds; check for progressively increased sound and air volume at air outlets.

3. Air leaks in system. 3. Check for air leaks with the engine at idle and the heater in its various con-trol positions. Remove obstructions or restrictions from the ducts as required.

4. Function control lever. 4. Check and adjust function control lever.

5. Heater valve. 5. Check the heater valve for proper operation. Repair or replace as necessary.

6. Heater hose(s) crossed or improperly 6. Route heater hoses properly. installed.

7. Heater hose(s) kinked, clogged, or 7. Remove hose restrictions or replace collapsed. as required.

8. Heater core plugged or restricted. 8. Flush heater core or replace as required.

9. Thermostat. 9. Check for proper operation and replace, if necessary.

10. Cowl vent air ducts. 10. Adjust control cable or replace as required.

Improper blower motor 1. Blown fuse. 1. Check fuse and replace, if necessary. operation. 2. No voltage to blower motor or switch. 2. Refer to Shop Manual for testing

procedures.

3. Wiring problem. 3. Refer to Shop Manual for testing procedures.

Too much heat. 1. Temperature control lever or cable 1. Check for binding and repair or binds, sticks. replace, if necessary.

2. Temperature control cable out of 2. Check and adjust as required. adjustment.

3. Heater valve malfunction. 3. Check and repair or replace, if necessary.

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CARGO BODY/CHASSIS/ELECTRICAL FEATURES POSTTEST

DIRECTIONS: Indicate the one correct answer for each question by circling one Jetter.

1. The diaphragm spring clutch in the Cargo vehicle is a hydraulically operated clutch. a. push-type b. pull-type c. crankshaft driven d. all of the above

2. The clutch pedal range of motion is controlled by a installed in the cab bulkhead. a. stop bolt b. clutch release lever c.· push rod d. lock pin

3. As the friction material on the clutch disc wears, the --------- and master cylinder will compensate for the additional clearance between the disc and the flywheel. a. slave cylinder b. hydraulic reservoir c. hydraulic line d. diaphragm spring

4. The clutch diaphragm spring is designed in a __________ shape to provide powerful bellville spring action. a. round, flat b. round, coiled c. square d. round, dish-like

5. The clutch release lever pulls back on the --:--c::----:-:-----,---,-, to disengage the clutch and allow the transmission to be shifted. a. release shaft b. clutch disc c. clutch cover d. release sleeve

6. Clutch pedal free travel should be about ---,-----,,------from the upper stop bolt if properly adjusted. a. 10-15 mm {.4-.6 in) b. 5-10 mm (.2-.4 in.) c. 0-5 mm (0-.2 in.) d. 10-20 mm (.4-.8 in.)

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7. Slave cylinder pushrod should be adjusted so that the distance between the lower mounting hole and the lock nut slot is ________ _

a 144-147 mm (5.6-5.8 in.) b. 135-138 mm (5.3-5.4 in.) c. 150-153 mm (5.9-6.0 in.) d. 147-150 mm (5.8-5.9 in.)

8. The power steering pump in the Cargo vehicle is _________ by the engine.

a. belt driven b. chain driven c. gear driven d. pressure driven

9. A connects the steering shaft to the steering gear input shaft and allows the cab to be tilted. a. steering column bracket b. universal joint c. ball bearing d. retaining pin

10. The standard Cargo brake system is

a. hydraulic b. full air c. air over hydraulic· d. hydraulic over air

11. The works in conjunction with the compressor unloading mechanism to main­tain predetermined maximum and minimum pressures in the brake system. a. governor b. primary reservoir c. secondary reservoir d. air inlet line

12. The compressor in the Cargo truck is a belt driven. --:----:-------• reciprocating piston design. a. double cylinder b. single cylinder c. triple cylinder d. self cooling

CARGO BODY/CHASSIS/ELECTRICAL FEATURES POSTTEST (continued)

13. The diaphragm area in the air chamber of the air/hydraulic intensifier is approximately _________ tim~s the master cylinder piston area. a. 15 b. 20 c. 12 d. 17

14. The air/hydraulic intensifier incorporates a sensor that tells the driver if is too low. a. air pressure b. hydraulic pressure c. hydraulic fluid level d. return spring pressure

15. The disc brake caliper in the Cargo truck is a dual piston, design. a. rail slider b. air actuated c. single cylinder d. pin slider

16. Air from the spring brake chambers is released through the when the parking brakes are applied. a. quick release valve b. safety valve c. relay valve d. parking brake control valve

17. The proper cut-out pressure for the governor in the Cargo brake system is ________ _ using the test gauge. a. 793-862 kPa (115-125 psi) b. 752-903 kPa (109-131 psi) c. 613-779 kPa (89-113 psi) d. 620-772 kPa (90-112 psi)

18. Which of the following service procedures should be performed on the air/hydraulic intensifier every month, 8000 miles, or 300 operating hours? a. Check mounting nut tightness b. Inspect hydraulic and air line fittings c. Check for proper fluid level in the reservoir d. All of the above

19. Front disc brake pads may easily be replaced by removing ________ _

a. approximately two-thirds of the brake fluid b. the front wheel and tire assembly c. the dampening plate on the caliper d. all of the above

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20. The front suspension of the Cargo vehicle is equipped with longer springs and a _________ to provide balanced, level turning. a. mounting bracket b. shackle bracket c. stabilizer bar d. shock absorber

21. Adjustment of the cab locking mechanism is made with the ________ _

a. vertical lever adjuster screw b. tilt lock handle c. cab release lever d. cab stay adjustment screw

22. The radiator in the Cargo is equipped with two in tank coolers: one for the transmission fluid and one for the _______ _

a. steering fluid b. brake fluid c. engine oil d. hydraulic clutch fluid

23. How many fuse links are in the Cargo charging system? a. Two b. Three c. One d. Four

24. The flow of coolant through the heater core in the heating system is controlled by the

a. function selector lever b. metering valve c. heater core valve d. inlet valve

25. When adjusting the temperature control cable, there should be about of exposed cable between the cable retaining clip and the valve lever. a. 0-5 mm (0-.2 in.) b. 5-10 mm (.2-.4 in.) c. 10-15 mm (.4-.6 in.) d. 15-20 mm (.6-.8 in.)