OPERATING MANUAL

FOR SCISSOR LIFT

MODEL ____________

SERIAL # _____________________

CYLINDER SERIAL # ___________________________

1089 County Road 26, P.O. Box 179 Marengo, Ohio 43334 www.MFSLTD.com

P: 800.919.2652 F: 419.253.2120

SCISSOR LIFT HOISTS

1089 County Road 26, P.O. Box 179 Marengo, Ohio 43334 www.MFSLTD.com

P: 800.919.2652 F: 419.253.2120

EXHIBITS

1. Model VL-6238M1

2. Model VL-5272

3. Description

4. Installation

5. Service

6. Safe Operation

7. Parts List for VL Hoist

8. Parts List for Cylinder Heads

9. Decal Application

10. Pilot Operated Check Valves

11. Application Considerations

12. Electrical System Requirements & Recommendations

13. Description

14. Parts Spec. Sheets

MODEL: VL-6238M1

· Self-contained unit · Telescopic cylinders connected between jack arm and lift arm

assemblies · Can be mounted on any truck chassis with minimum cutting and reworking

chassis · No forward or backward travel of body throughout lift cycle · Hoist can be

mounted in forward or reverse position, for front or rear loading, placing lift directly

under centerline of gravity, assuring added stability · Body lengths from 13’ or 18’ · No

CA restrictions other than required for weight distribution. SPECIFICATIONS: Net payload: 6 tons (12,000 lbs.) Height of lift above ground: 14’0” (168”) Hoist mounting height: 15” Hydraulic pump and valve assembly: 20 GPM capacity – dual shaft gear pump – balanced spool valve Hoist cylinders: Two, 6”, two-sections telescopic, 38” stroke Displacement: 1.856 cu. in. (8 gal.) Hoist may be mounted as shown or in reversed position (hinge to front) Hoist also available with electric controls Lift arms: 7” x 4” x 3/8” Wall Rectangular Tubing amply reinforced Approximate weight including lift frame: 3,360 lbs. Recommended chassis – GVW: 21,000 lbs. to 23,000 lbs. Recommended frame section modulus: 14.0 Recommended dual tire size: 9.00 x 20 OPTIONS: Chrome plated cylinder sleeves Manual or hydraulic outriggers

MODEL: VL-5272

· Hydraulic pump – dual shaft gear type · Balanced spool type valve control valve ·

Ruggedly constructed main lift frame – I beam side rail with four, full depth cross

members eliminate side sway · Heavily reinforced jack arms · Safe operating for (1) off-

center loading – 6,000 lbs. in any quarter floor area (2) dropping impact 2,800 lbs., 8”

down on rear edge of body (3) wind loads up to 50 mph · Easily mounted · Built-in end

dump arrangement by pulling two pins to convert to end dumping · Body lengths from

12’ to 16’ on 102” to 144” CA. SPECIFICATIONS: Net payload: 6 tons (12,000 lbs.) Height of lift above ground (varies with chassis): 14’0” (168”) Hoist mounting height: 14” Hydraulic pump and valve assembly: 20 GPM capacity – dual shaft gear pump – balanced spool valve with mechanical hoist stop Hoist cylinders: Twin Telescopic – 3 sleeve, 5” dia. x 72” stroke, high pressure Displacement: 7.4 gal. Overload relief valve set at 2,500 PSI Jack arms: 8” weldment – heavily reinforced Main lift frame: 8” I beam side rails; 4 full depth cross members provide stiffness and

eliminate sway Approximate weight including lift frame: 3,900 lbs. Recommended chassis – GVW: 21,000 lbs. to 23,000 lbs. Recommended frame section modulus: 14.0 Recommended dual tire size: 9.00 x 20 OPTIONS: 6” dia. hoist cylinders Chrome plated sleeves Manual or hydraulic outriggers Electric controls

DESCRIPTION

Marengo Fabricated Steel’s Scissor Lift Hoist is a hydraulically actuated scissor

type lifting mechanism. At full extension the lift extends 14’ above the ground (with a

chassis length of 36”) vertically and capable of lifting a load of 12,000 lbs. The lift may

also be used in a normal dump mode; this is accomplished by removing two (2) pins from

the lifting linkage. Vertical extension and dumping are separate functions and CANNOT

be accomplished in combination.

The lifting mechanism is intended for use on truck chassis; it may, however be

used in stationary situations with special mounting. Body specifications are adapted to

the owner’s individual requirements; the body length may range from twelve (12) to

sixteen (16) feet. Optional equipment for the scissor lift includes (1) manual outriggers,

(2) hydraulic outriggers, and (3) remote electric controls.

The components of the scissor lift system are described as: structural, hydraulic

and power source. The structural part consists of a full sub frame, lift arms, jack arms,

cylinder mounts and longitudinal mounts for the body. The hydraulics consist of two (2)

single acting telescopic cylinders, one (1) gear pump with 3 position spool valve and the

lines, fittings etc. to support the hydraulic system. The power source engine and PTO are

not supplied.

INSTALLATION

The Scissor Lift should be installed on a single axle chassis with the minimum

requirements detailed on the Application Data Sheet. Caution: Do not attempt installation

of a body in excess of 16 ft. and do not exceed recommended body pivot dimensions.

Before beginning the installation consult the mounting drawing and the suggestions for

installation. The hoist should bolt in place without cutting or fitting. If there is binding or

misalignment consult Marengo Fabricated Steel before attempting any alteration. As the

final part of installation and after any painting apply decals. Locate the two load limit

decals on each jack arm so they are clearly visible. The two operation and maintenance

decals must be located to suit the installation and again be clearly visible to the operator.

SERVICE

All parts should be greased on a regular schedule (see lubrication chart). For the

hydraulic system an industrial fluid with anti-wear, rust protection plus high heat

resistance and low pour point is recommended. An example for acceptable use is

Industron 44 (Sohio) or any commercial equivalent. Under no circumstances should any

hydraulic fluid be thinned with kerosene or allowed to be water contaminated.

All replacement parts should be factory approved and ordered through the dealer.

Parts ordering information for the vertical lift pump and hydraulic cylinders is included in

this manual.

Many maintenance problems will be avoided through understanding the scissor

lift. The mechanical structure has several metal bearing pivot points that require good

lubrication to prevent excessive wear. Misalignment or bent metal arms and/or

undersized pins create excessive mechanical stress. Air in the hydraulic system can cause

uneven operation of the hoist. Air can be eliminated by bleeding the cylinders,

maintaining a minimum oil level of 2 inches (with lift extended) in the reservoir and

avoiding unnecessary running of the PTO. Body creep may be caused by air in the system

and/or back bleeding through the pump valve. Because the valve is not 100% leak free,

some creep can be expected. For long periods of extension, it may be practical to

mechanically block the body in position. While inspecting or servicing the vertical lift

NEVER work under the lift without installing safety blocking.

SAFE OPERATION

The Scissor Lift is designed to safely raise loads not exceeding 12,000 lbs. To

assure optimum safe use, the operator should observe the following procedure:

1. Distribute load evenly on truck bed.

2. Locate truck on firm level ground. At construction sites, use brick, block,

timbers, etc. to level truck.

3. Lower outriggers (where applicable).

4. Pull link pins must be in place before raising.

5. Start truck engine and engage PTO. Accelerate engine to slightly above

idle. Activate hoist by pulling lever on floor of cab toward operator.

6. Observe hoist as it raised for proper operation. Lower immediately if any

misalignment is observed.

7. When hoist is extended to desired position, move hoist control lever to

HOLD and disengage PTO.

8. Lower hoist by moving lever forward (away from operator). Truck engine

does not have to run.

9. NEVER move truck with scissor lift extended.

The operator should be trained on the job with the above procedure by a qualified

supervisor. He should be aware of the safety decals and their content. This manual should

be available to the operator at all times.

VL-5272 SCISSOR LIFT HOIST ASSEMBLY PARTS LIST

Symbol Part # Description # Req. 1 A-112881 Subframe Assembly 1 2 A-212886 Subframe Side Plate Assembly 1P/1L 3 411246-* Steel Sill (specify length) 2 4 1-112880 Lift Arm Assembly 1 5 49924 Hinge Pin (Lift Arm to Subframe) 2 6 47868-8 Cotter Pin ½ x 2 lg. 4 7 A-212885 Body Understructure 1 8 0703 Zerk Fitting – 1/8 Straight 4 9 49913 Roller 2 10 111776-18 Washer 2 11 41320 Washer 2 12 43479-175 Snap Ring 2 13 39908 Roller Hook 2 14 412892 Filler (optional) 2 15 A-214862 Jack Arm Assembly 1R/1L 16 47868-16 Cotter Pin ½ x 4 lg. 2 17 412884 Hinge Pin (Jack Arm to Understructure) 2 18 47810-24 Capscrew ½ N.C. x 3 lg. 6 19 47894-8 Hex Nut ½ N.C. 6 20 47849-8 Lockwasher ½ 6 21 A-312878 Pull Link Assembly 2 22 A-412882 Pull Link Pin 2 23 42271 Chain – Pin 2 24 412883 Pin (Pull Link to Side Plate) 2 25 411018-3-1/2 Guide, Pull Link 2 26 112891-1 Support Angle 3 x 2 x 3/8 x 4 lg. 2 27 A-312889 Cylinder Support Assembly 1 28 47273-5-1/2 Pin, Cylinder Pivot 2 29 47867-8 Cotter Pin 3/8 x 2 lg. 8 30 30574004 Telescopic Cylinder 2 31 47273-5 Pin (Jack to Lift Arm) 2 32 47815-16 Capscrew ¾ N.F. x 2 lg. 16 33 47893-12 Hex Nut ¾ N.F. 16 34 47849-12 Lockwasher ¾ 16 35 47813-14 Capscrew 5/8 x 1-3/4 lg. 6 36 47893-10 Hex Nut 5/8 N.F. 6 37 47849-10 Lockwasher 5/8 6 38 A-113589 Oil Tank Mounting Parts 1 39 A-311563 Oil Tank Only 1 40 47809-14 Capscrew ½ N.F. x 1-3/4 lg. 8 41 47893-8 Hex Nut ½ N.F. 8 42 47849-8 Lockwasher ½ 8 43 49914 Mounting Angle 2

VL-5272 SCISSOR LIFT HOIST ASSEMBLY PARTS LIST cont.

Symbol Part # Description # Req. 44 49915 Filler Plate 2 45 A-313436-* Front Cross Sill Assembly 1 46 A-212163 H.D. Pump & Valve Assembly with Relief 1 47 46104-30 Pump Brace 1 410514 Pump Mounting Bracket 1 410515 Pump Mounting Angle 1 419104 Gusset 1 48 47814-14 Capscrew 5/8 N.C. x 1-3/4 lg. 2 47849-10 Lockwasher 5/3 2

·From Oil Tank to Pump· 49 24886 L.P. Hose 1 x 3/8 1 9013B Elbow 1 x 90 1 90120 Nipple 1 x 2 1 90210 Adaptor Union 1 x 90 1 90003 Reducing Bushing 1-1/2 x 1 1

·From Pump to Jacks· 50 23381 H.P. Hose ¾ x 24 2 25258 H.P. Hose ¾ x 48 (16’ Bed) 1 24887 H.P. Hose ¾ x 30 1 90181 H.P. Reducing Bushing 1 x ¾ 3 90113 E. H. Nipple ¾ x 2 4 90702 H.P. Elbow ¾ x 90° 2 90703 H.P. Elbow ¾ x 45° 2 90701 H.P. Tee ¾ 1 90323 Adaptor Union ¾ 3

PARTS LIST FOR CYLINDER HEADS 4 – STAGE CYLINDER

Let. P. Des. Part # 7400 6400 A Bearing 35140 35130 B Bearing 35150 35140 C Bearing 35160 35150 D Bearing 35170 35160 E Rod Seal 35371 35361 F Rod Seal 35361 35351 G Rod Seal 35351 35341 H Rod Seal 35341 35330 I Ret. Bush. 35072 35062 J Ret. Bush. 35062 35052 K Ret. Bush. 35052 35042 L Ret. Bush 35042 35032 M Ret. W. 35280 35270 N Ret. W. 35270 35260 O Ret. W. 35260 35250 P Ret. W. 35250 35240 Q R. Wiper 35771 35761 R R. Wiper 35761 35751 S R. Wiper 35751 35741 T R. Wiper 35741 35731

PARTS LIST FOR CYLINDER HEADS cont. 3 – STAGE CYLINDER

Let. P. Des. Part # 7300 6300 5300 4300 A Bearing 35150 35140 35130 35120 B Bearing 35160 35140 35130 35120 C Bearing 35170 35160 35150 35140 F Rod Seal 35371 35361 35351 35340 G Rod Seal 35361 35351 35340 35330 H Rod Seal 35351 35341 35330 35320 J Ret. Bush. 35072 35062 35050 35040 K Ret. Bush. 35062 35052 35040 35030 L Ret. Bush 35032 35042 35030 35020 N Ret. W. 35280 35270 35260 35250 O Ret. W. 35270 35260 35250 35240 P Ret. W. 35260 35250 35240 35230 2 – STAGE CYLINDER

Let. P. Des. Part # 4200 3200 A Bearing 35130 35120 B Bearing 35140 35130 C Rod Seal 35340 35330 H Rod Seal 35330 35320 K Ret. Bush. 35040 35030 L Ret. Bush. 35030 35020 O Ret. W. 35250 35240 P Ret. W. 35240 35230 Let. P. Des. Part # 7300 6300 R R. Wiper 35771 35761 S R. Wiper 35761 35751 T R. Wiper 35751 35741

DECAL APPLICATION

Decals must be applied to a clean dry surface. To apply, separate decal at corner

of backing and peel back approximately 3 inches. Locate decal and press in place while

slowly removing remainder of the backing, pressing decal firmly in place.

NOTE: Decal material is destructible and cannot be removed without tearing.

PILOT-OPERATED CHECK VALVES (for model V20-LO valve only)

Model V20-LO work sections are designed with double pilot-operated check

valves. These pilot operated checks will lock a cylinder or part of a circuit – without

leakage – when the control valve spool is in the neutral position. When the spool is

shifted to a power position, pressurized oil is directed to one work port. Return oil into

the opposite work port is momentarily blocked until pilot pressure unseats the check.

Metering characteristics of valve spools are slightly diminished when using these pilot-

operated check valves.

These checks are used on applications such as clamps, outriggers, and elevated

work platforms where internal fluid leakage could affect the operation of the system. The

functions of a 4-Way Section and a pilot-operated check or lock-out in one valve housing

are combined in one section.

The spool is a 4-way, 3-position modified free flow spool. This spool is the same

as F4, 4-way, 3-position free flow except the free flow feature is restricted. Free flow

prevents any pressure build up between the pump and the pilot operated check when the

valve spool is in the neutral position.

APPLICATION CONSIDERATIONS

Some points to consider when designing the solenoid valve into a hydraulic system are:

1. The standard free flow spool cannot be used with a solenoid actuator. The

spool timing is such that as the spool begins to shift the pump is open to tank

dropping pressure below 200 PSI and stopping the spool. A modified free

flow spool is provided for solenoid operated valve sections.

2. The 4-way, 4-position float spool cannot be used with a solenoid actuator.

3. The solenoid actuator requires a differential pilot pressure of 200 PSI above

the exhaust line back pressure. The pressure reducing valve senses back

pressure and will provide a pilot pressure of 200 to 300 PSI above the back

pressure. Back pressure should not exceed 300 PSI. This will eliminate the

possibility of exceeding 600 PSI pilot pressure in the solenoid actuators.

4. For over center or light load applications: if the pressure requirement at the

powered work port is less than 200 PSI, the pressure at the actuator drops to

that same requirement. When that happens, the centering spring begins to

move the spool back to neutral. If the solenoid remains actuated, the spool

will begin to “hunt”.

Use a restrictor in the work port to maintain pressure requirements above 200

PSI at all times.

5. A power beyond option is not available in the outlet cover of V20 solenoid

operated valve assemblies. The power beyond option is available in the utility

section. If a power beyond option is used in the utility section, the pressure

build-up valve must be located in the downstairs valve assembly.

ELECTRICAL SYSTEM REQUIREMENTS AND RECOMMENDATIONS

Switches:

The solenoid switch must meet the following requirements:

1. Must be D.C. rated.

2. Electrical rating should be at least 3 AMPS. However 6 AMPS is suggested.

3. Use a double-pole, double-throw (DPDT) switch for most applications.

Exceptions are:

Closed center.

Separate pilot source is used (no internal pilot). Single-pole, double-throw

switches (SPDT) are to be used for the exceptions, because a pressure build-up

valve is not required in the circuit for these types of applications.

Types of Switches:

Several types are available – rocker, rocker with detent, toggle with detent, push

button, etc. It makes no difference which type is used as long as the switch has been

selected meets requirements outlined above.

Wiring

It is recommended that stranded copper wire be used. The size of wire primarily

depends on the length that is required. Keep in the mind that the solenoid power

requirements must be met. The longer the length, the more current drop there will be.

Generally, 16 gauge wire can be used for lengths up to approximately 80 feet and

14 gauge for lengths up to 100 feet.

Wire classification can be found in an SAE handbook under the heading of “SAE

J558, (a low tension cable)”.

Terminals

The customer must supply two female spade terminals, Packard Part No. 2965470

and one panel connector. Packard Part No. 2965490 or equivalent for each solenoid.

Note that special tools for crimping terminals are available from most electrical

supply stores.

DESCRIPTION

Solenoid-Controlled Actuator The solenoid-controlled actuator assembly contains two, 3-way, normally closed solenoid-operated valves and a pilot-operated piston mounted directly to the control valve spool. When a solenoid is energized, the solenoid valve opens; pilot pressure at 300 PSI above tank line pressure is applied to one side of the piston causing the spool to shift from its neutral position. When both solenoids are de-energized, both sides of the piston are open to exhaust and the spool is spring-returned to neutral. A needle valve, externally adjustable, meters the exhaust pilot flow to control the spool’s rate of travel. Solenoid coils are molded, impervious to moisture, continuous duty rated, class H (180°C), and are supplied with two male, spade terminals. Customer must supply two female spade terminals, Packard Part No. 2965470 and one panel connector, Packard Part No. 2965490 or equivalent, for each solenoid. Utility Section A pilot source of 2 to 4 GPM at 300 PSI is required to operate each actuator and may be supplied by the customer from a source external to the control valve. Or, the pilot source may be supplied by a utility section which is assembled as an integral part of the control valve. The utility section incorporates all components required to operate the actuators, eliminating the need to supply any external pilot lines. The entire control valve assembly is self-contained.

The utility section must be installed between last work section in a directional control vale assembly ant the right or outlet cover. Both open center and closed center applications are available. The tank port may be located in either the inlet or outlet cover of the control valve assembly. The following component parts are included with the utility section: Solenoid-Operated Pressure Build-Up Valve must be wired in parallel with each solenoid-controlled actuator. Because of the low open center pressure drop found in the Model V20 Direction Control Valve, the pressure build-up valve is necessary to increase the oil pressure required to shift the valve spools.

For closed center applications, the pressure build-up valve is not required. However, the system must have a stand-by pressure of 300 PSI available. Pressure Reducing Valve reduces oil pressure to the solenoid-controlled actuator to 300 PSI at 2 to 4 GPM. Uni-Directional Check Valve installed in the solenoid-controlled actuator return or exhaust port to prevent system shock peaks from affecting the actuator. Hydraulic Systems with a Customer-Supplied External Pilot Source The utility section is not required if the hydraulic system has a 2 to 4 GPM, 300 PSI pilot source available. Pilot tubing must be a minimum of 3/8” tubing with SAE No. 6 (9/16” – 18) fittings. The pilot exhaust line should be plumbed directly back to the reservoir. If teed into the control valve return line, a one-way check valve must be installed in the pilot line to prevent shock peaks from affecting the actuators. Manual Handle Assembly Handles for manual operation of Gresen Directional Control Valves may be installed on the opposite end of the spool on which the solenoid-controlled actuator is mounted. This gives the operator a choice of either remote electrical control or manual control. Provision for manual operation also offers a standby alternative in case of electrical power failure.