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2ZD 225B EXCAVATOR Testing & AdjustingMedia Number SENR3465-01 Publication Date 1987/12/01 Update Date 1995/12/06

Testing And Adjusting

Performance Checks

Analysis

In an analysis of machine performance, comparison of engine rpm under different conditions of loadingis of very little value. There are conditions, however, when a change in engine rpm can be an indicationof the cause of a problem.

1. If the engine rpm for Test 1 (from the chart) is too high, check the set point (balance point). Theengine set point is an adjusted specification and is important to the correct operation of the engine andhydraulics. High idle rpm is NOT an adjusted specification. Set point (formerly balance point) is fullload rpm plus an additional 20 rpm. Set point is the rpm at which the fuel setting adjustment screw andstop just start to make contact.

NOTE: Engine speed information should be found on the Engine Information Plate. If the EngineInformation Plate is not available, see the Fuel Setting And Related Information Fiche.

The 6V4060 Engine Set Point Indicator Group with the 6V2100 Multitach is recommended to check theset point. For more detailed instructions on the set point indicator and its use, see Special InstructionsForm No. SEHS7931.

To prevent damage to pumps and motors, it is very important thatthe cases are filled with hydraulic oil at least to the fill port beforeoperation.

Página 1 de 46Copyright 1991, 2015 Caterpillar Inc. All Rights Reserved.

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Set Point Indicator

Set Point Indicator (Used With Multitach)

2. Bent-axis piston pump displacement must always be the same.

Output from the pumps must always be the same from each pump, when both pumps are operated at thesame pressure.

If the outputs are not the same, this can be seen in a difference in rpm between Tests 2 and 3 in the chart.It will also make a difference in Test 4. Use the cycle times to check on the flow from the pumps.

3. Maximum machine performance and efficiency are possible only when there is a balance betweenhorsepower needed to do the job and horsepower available from the engine. If both of the bent-axis

piston pumps were operated under conditions of maximum flow (output) and pressure, the horsepowerneeded would be more than double the amount available from the engine. If some way to control theload on the engine was not installed on the machine, the engine would lug to a stop. The pump controlsystem is designed to keep an exact relationship between engine rpm, pump signal pressure and port

plate angle (pump output) at all times.

Release Of Pressure

Release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydrauliclines or components are disconnected or removed. Follow this procedure:

1. Fully retract the rod in the stick cylinder.

2. Adjust the position of the bucket so that it will be flat on the ground when the boom is lowered.

3. Lower the boom until the bucket is flat on the ground.





4. Shut off the engine and put the lever for the selector valve in the LOCK position.

NOTE: Small valves (bleed valves) have been installed in the boom, stick and bucket circuits.

5. Move the control levers for boom, bucket, stick and swing to all positions. This will relieve any pressure that might be present in the pilot system.

6. Slowly loosen the filler cap on the hydraulic tank and release the pressure.

7. Tighten the filler cap back on the hydraulic tank.

8. Slowly open the bleed valves in the lines to the boom, bucket and stick cylinder.

9. Tighten the bleed valves.

10. The pressure in the system has been released and lines and components can be removed.

NOTE: There are no bleed valves in either the swing or track circuits. Normally, any pressure that

might be trapped in these lines, will bleed off through the motors.

Valve Stem (External Adjustment Type)

Housing For Shim Adjustable Type Stems (Typical Illustration)

(1) Housing (2) Springs (centering) (3) Shims (4) Retainers





Housing For Plunger Adjustable Type Stems (Typical Illustration)

(5) Stem (6) Springs (centering) (7) Retainer (8) Threaded plunger (9) Retainer (10) Housing (11) Nut

The following machines have control valves that are adjusted by an external threaded plunger (screw)(8) instead of adjustment by internal shims (3).

Housing (1) for shim adjusted valves contain return spring (2), retainers (4) and shims (3) for bothdirections of stem movement. Housing (10) for plunger adjusted valves contain return springs (6),retainers (7) and (9), threaded plunger (8) and nut (11). Housing (10) is used on each end of the controlvalve stem (5) since it adjusts for only one direction of stem movement.

Housing Modification (For Hydraulic Testing And Adjusting)





Modified Housing For Hydraulic System Testing (Screw Adjusted Type Only)

(5) Stem (7) Retainer (12) Spacer (13) Bolt 5P7336

To load the hydraulic system for testing purposes, the control valve stick and stick crossover valves areused to load the system (see the following sections). A modification can be made to the screw typehousing of the valves so that the system can be loaded for hydraulic testing.

Measure distance (A) between the end of plunger (8) and nut (11) for each of the valves. Duringreassembly, distances (A) will be used to get the correct adjustment.

Remove housing (10), plunger (8) (using an allen wrench), nut (11) and retainers (7) and (9).

Fabricate a 76 mm (3 in.) long by 19 mm (.75 in.) diameter spacer (12). Position spacer (12), retainer(7), 5P7336 Bolt (13), and springs (6) in housing (10).

When the tests are complete, remove the retainer, spacer, springs and bolt. Reinstall the retainers, plunger, springs, housing and nut. Adjust plunger (8) to distance (A).

Adjustment Of Hydraulic Horsepower

Tools Needed:

6V3121 Multitach Group.

6V4161 Pressure Gauge Kit.

5P7336 Bolt (9/16-18 thread) 101.6 mm (4.0 in.) long (2 each).

6V4060 Set Point Indicator.





This procedure can be used to check and adjust the hydraulic horsepower (HHP) of the machine. Itassumes that both implement pumps are in good condition and are adjusted for an approximatemaximum flow as shown below:

NOTE: This procedure cannot be used to check the factory settings.

Tool Installation And Machine Preparation

1. Put the machine on level ground with the boom in position over the track motors and the swing lock pin in the LOCKED position.

2. Raise the boom and put the stick OUT and the bucket CLOSED (stick cylinder fully retracted and

bucket cylinder fully extended).

3. Lower the boom until the bucket is on the ground.

4. Put the selector lever in the LOCK position (down). Leave it in this position for the rest of the test.

5. Stop the engine.

6. Check the level of the hydraulic oil in the tank. It must be above the ADD level.

Left Front Of Engine (2ZD And 1GF)





(1) Tack drive

7. Install the cable of 6V3121 Multitach on tack drive (1). Install cables from set point indicator (6) torack contact (2), ground (3) and battery positive (7).

Top Front Of Engine (2ZD And 1GF)

(2) Rack contact (3) Ground

Test Setup (Partial)

(4) Bolt (stick crossover) (5) Bolt (stick) (6) Multitach and set point indicator (7) Battery positive

8. Remove the plugs from the end housings on the stick and stick crossover valves. [If valves areexternal adjusted type, see the section Valve Stem (External Adjustment Type).]

9. Install the 5P7336 Bolts (4) and (5) (9/16 in.) in the housings.

10. Turn the bolts in until they touch the end of the spools.

NOTE: Turn the bolts in (CW) or out (CCW), whenever necessary, during the procedure to load orunload the implement pumps.

11. Connect a 50 000 kPa (7500 psi) pressure gauge to each of the pressure taps (10) and (9) on the frontand rear pumps.





Pressure Tap Locations

(8) Summing valve pressure port (9) Rear pump pressure port (10) Front pump pressure port (11) Pumpactuator pressure port

12. Connect a 28 000 kPa (4000 psi) pressure gauge to pump actuator pressure port (11).

13. Connect a 50 000 kPa (7500 psi) pressure gauge to summing valve pressure port (8). Use an M12-

7/16 in. adapter (part number 8T7860) and seal (part number 6V9028) if metric fittings are not available.

NOTE: Be sure the hoses are long enough so the gauges can be read by the person adjusting the bolts inthe main control valve end housings. It is very important that the gauges be accurate.

14. Start the engine and pull the governor control lever to the full throttle (high idle) position.

15. Get the temperature of the hydraulic oil to 49 to 66°C (120 to 150°F)(1/4 to 1/2 into the green bandon the instrument panel temperature gauge).

NOTE: The oil can be heated by turning the bolt in either the stick or stick crossover control valve in(clockwise) until the pressure gauge reads between 10 000 and 15 000 kPa (1500 and 2000 psi).

16. If used, remove the cardboard in front of the cooler after the temperature gauge is 1/4 into the green band.

Keep the governor control at ful throttle for the rest of the test and adjustment. Decrease the pressure byturning the bolt out (counterclockwise) on the crossover valve.

Engine Full Load RPM

NOTE: If an adjustment is made, the high idle rpm will be affected.

17. Install a 1/4-20-1 1/8 in. blocker bolt (grind head off) into the summing valve to neutralize theoperation of the summing valve (to keep pump from destroking).





Location For Blocker Bolt

18. Start the engine and pull the governor control lever to the rear (wide open). Load the stick circuitdown until set point indicator (6) OVERRUN light just goes OFF (or voltmeter reads 1 to 2 volts). Thefull load rpm is equal to the set point rpm read on the multitach minus 20 rpm. Full load rpm (rated rpm)should be 2200 ± 10 rpm for 1AG1-UP, 1GF-UP, and 2ZD1-UP; and 2000 ± 10 rpm for 3YD1-UP.

19. If an adjustment is needed, turn the high idle screw clockwise to increase and counterclockwise to

decrease the full load rpm (set point rpm minus 20 rpm).

20. Remove the blocker bolt from the summing valve.

Pump Hydraulic Horsepower

21. Load both pumps approximately an equal amount until there is a large rise (needle pops) in pumpactuator pressure [approximately 2050 to 3450 kPa (300 to 500 psi)]. At this point, the average pressurefor each pump should be approximately 11 200 kPa (1624 psi) for 2ZD1-UP, 3YD1-UP, and 1GF1-UP;or 10 500 kPa (1522 psi) for 1AG1-UP.

NOTE: Custom 180 machines (2ZD and 1GF that are turbocharged) have an average pressure of 12 500kPa (1825 psi)

NOTE: At this point, the average of the pump pressures at (9) and (10) should equal the pressure atsumming valve pressure port (8). If not, the summing valve is not operating correctly. The problem must

be corrected before continuing the checks and adjustments.

Pump power adjustment screw (12) determines the point at which destroking occurs. If necessary, adjustthe pump power adjustment screw to get the correct pressure. Turn the screw clockwise (CW) toincrease the summing pressure and counterclockwise (CCW) to decrease pressure. Adjust screw (12)first, then load the pumps again. Repeat this sequence until the pressure is correct.

NOTE: 1/4 turn of screw (12) will change the pressure approximately 750 kPa (110 psi).

22. Record the engine speed at this pressure. This speed should be 2010 to 2080 rpm for 3YD1-UP; or2210 to 2280 rpm for 2ZD1-UP, 1GF1-UP and 1AG1-UP.





Double Pump Housing (Top View)

(12) Pump power adjustment screw (13) Torque slope screw

23. Load both pumps to an average pressure of 20 700 ± 690 kPa (3000 ± 100 psi).

24. The engine speed should be ± 10 rpm of that recorded in step 22.

25. If the above speed is either too low or too high, adjust torque slope screw (13), then repeat steps 21through 24. Turn torque slope screw (13) clockwise (CW) to reduce engine speed and counterclockwise(CCW) to increase engine speed.

26. If the speed is still too low, then the problem could be:

a. Summing valve check valves are not opening and/or closing properly.

b. Summing valve spool is not shifting.

c. Pump regulator valve and/or respective bore in actuator piston is worn or damaged.

d. Lever assembly is not moving correctly.

e. Worn or bad actuator seals.

27. If the speed is still too high, then the problem could be:

a. Bad spring on actuator piston.

b. Pumps worn.

c. Bad spring in lever assembly.

d. System relief valve is set too low.

Adjustment Of Maximum Displacement Angle





Maximum Angle Displacement Screw (Typical View)

This screw controls the maximum output flow of the pump. It is factory set to the maximum output flowof 208 liter/min (55 U.S. gpm) (2ZD, 1GF, 3YD) [229 liter/min (60.5 U.S. gpm) (1AG)] and should notneed any adjustment. These flows occur at an engine speed of 2000 rpm for 3YD (2200 rpm for 1GF,1AG and 2ZD). If turned in clockwise (CW), it will reduce output flow and affect the results of thePump Hydraulic Horsepower adjustment procedure.

With the engine stopped and the screw backed out, turn the screw in until increased pressure is felt asthe screw meets the actuator piston. This should be maximum displacement angle (3YD and 1AG). For1GF and 2ZD, the screw should be turned in an additional 4.5 mm (.176 in.) after increased resistance isfelt.

Adjustment Of Minimum Displacement Angle

Minimum Angle Displacement Screw

If the minimum displacement angle adjustment screw is turned in clockwise (CW) too far, the enginecould possible stall during operational destroking of the pump.

The factory setting of the screw is normally 18 mm (.71 in.) above the jam nut.

Adjustment Of Main Relief Valve

Make reference to WARNING on first page of ExcavatorHydraulic system Testing And Adjusting section.





Pressure Taps For Pressure Of Main System

(1) Location of pressure tap for circuits of rear pump supply (2) Location of pressure tap for circuit offront pump supply

Use Steps 1 through 9 to check and make adjustment of the opening pressure of the relief valve in themain system oil.

Use high pressure testing equipment only. Pressure can be morethan 31 000 kPa (4500 psi).





Relief Valve For Main System Oil

(3) Relief valve

1. Install pressure gauge in location (1) and/or (2).

2. Screw plunger (4) in on the track brake valve until the spool is blocked.

3. Start the engine.

4. Move the hand lever for control of stick movement to the STICK OUT or IN position and hold itthere after the stick cylinder is either fully extended or retracted. The oil pressure at location (1) must beaccording to the setting listed in the chart.

5. Move the hand lever for control of boom movement to the BOOM RAISE or LOWER position andhold it there after the boom cylinders are either fully extended or retracted. The oil pressure at location(2) must be the same as above.

Cross-Section Of The Track Brake Valve





(4) Plunger

6. If the oil pressures at locations (1) and (2) are not the same, make an inspection of the check valves inthe combiner valve.

If the oil pressures at locations (1) and (2) are not within specification, remove cover (7) and add/orremove shims (8). Each 0.12 mm (.005 in.) shim will change the opening pressure approximately 310kPa (45 psi). Add shims for a higher opening pressure and remove shims for a lower opening pressure.

7. Push down on either of the foot pedals for machine travel. The oil pressure at locations (1) and (2)must be 31 000 ± 1030 kPa (4500 ± 150 psi).

8. If the pressure is other than mentioned above, add or remove shims (9).

9. Unscrew plunger (4) in the track brake valve until the spool operates normally.

Combiner And Main Relief

(5) Plug (6) Spool (7) Cover (8) Shims (9) Shims

Adjustment Of Line Relief Valves

Make reference to WARNING on first page of the Testing AndAdjusting section.

Extreme caution must be used when testing the line relief valves.These valves are set to open at 33 000 kpa (4800 psi) except the





When testing the line relief valves, spool (6) must be put in its reverse position.

Remove plug (5) and spool (6). Install spool (6) end for end (reverse position to that shown) and installthe plug. This stops the oil flow to the pilot valve. The oil pressure in each circuit is now limited by theline relief valve in that circuit.

1. Move the hand lever for control of boom movement to the BOOM RAISE position and hold it thereafter the boom cylinders are fully extended. The oil pressure at location (2) must be 34 500 ± 690 kPa

(5000 ± 100 psi), the opening pressure of the line relief valve in the boom check and relief valve.

If it is necessary to test the line relief valve for boom LOWER, remove it and install it in one of theother circuits. DO NOT USE THE BOOM LOWER CIRCUIT FOR TESTING. The opening pressuremust be 33 000 ± 700 kPa (4800 ± 100 psi).

2. Move the hand lever for control of bucket movement to the BUCKET OPEN position and hold itthere after the bucket cylinder is fully retracted. The oil pressure at location (2) shows the opening

pressure of line relief valve in the outer end of the bucket control valve. The opening pressure must be33 000 ± 700 kPa (4800 ± 100 psi).

Move the hand lever for control of bucket movement to the BUCKET CLOSE position and hold it thereafter the bucket cylinder is fully extended. The oil pressure at location (2) shows the opening pressure ofthe line relief valve in the inner end of the bucket control valve. The opening pressure must be 33 000 ±700 kPa (4800 ± 100 psi).

3. Screw plunger (4) in on the track brake valve until the brake valve spool is blocked.

4. Push down on the pedal for FORWARD travel and hold it down. Move the hand lever for control ofsteering to full STEER LEFT position and hold it in that position. The oil pressure at location (2) showsthe opening pressure of the line relief valve on the outer end of the control valve for movement of theright track. The oil pressure at location (1) shows the opening pressure of the line valve at the inner endof the control valve for the movement of the left track.

5. Push down on the pedal for REVERSE travel and hold it down. Move the hand lever for control ofsteering to full STEER RIGHT position and hold it in that position. The oil pressure at location (2)shows the opening pressure of the line relief valve on the inner end of the control valve for movement ofthe right track. The oil pressure at location (1) shows the opening pressure of the line relief valve at theouter end of the control valve for the movement of the left track.

The opening pressure of all line relief valves tested in Steps 4 and 5 must be 38 000 ± 700 kPa (5500 ±100 psi).

track circuits which are set to open at 38 000 kPa (5500 psi).Under conditions of tolerance buildup these pressures canexceed 42 880 kPa (6200 psi).

The procedure that follows is to be used only if it is absolutelynecessary.





6. Unscrew the plunger in the track brake valve until the brake valve spool operates normally.

7. Move the hand lever for control of stick movement to the stick out position until the stick cylinder isfully retracted and hold. The oil pressure at location (1) shows the opening pressure of the line reliefvalve at the outer end of the stick control valve. Move the hand lever for control of stick movement tothe STICK IN position until the stick cylinder is fully extended and hold. The oil pressure at location (1)shows the opening oil pressure of the line relief valve at the inner end of the stick control valve. Theopening pressure of the line valves must be 33 000 ± 700 kPa (4800 ± 100 psi).

NOTE: Drop the swing lock pin into the LOCKED position.

8. Move the hand lever for control of swing movement to the SWING RIGHT position and hold. The oil pressure at location (1) shows the opening pressure of the line relief valve for swing RIGHT. Move thehand lever for control of swing movement to the SWING LEFT position and hold. The oil pressure atlocation (1) shows the opening pressure of the line relief valve for swing LEFT. The opening pressure ofthe line relief valves must be 17 600 ± 1030 kPa (2550 ± 150 psi).

Line Relief Valve (Example shown is from the line relief for swing)

(10) Shims

All line relief valves are the same except for the number of shims (10). One of the shims (10) willchange the opening pressure of the line relief valve (785 kPa (114 psi) in all cases except the swing. Oneshim in the line relief for swing will change the opening pressure 840 kPa (122 psi).

Adjustment Of Pilot Relief Valve

Use steps 1 through 4 to check and make adjustment of the relief valve in the pilot system.

1. Install pressure gauge at location (1).

2. With the engine running between 1000 rpm and high idle, the pressure at (1) must be 2300 ± 170 kPa(335 ± 25 psi).





Test Location For Pressure Of Pilot System

(1) Location for pressure gauge

Relief Valve For Pilot System

(2) Relief Valve

Cross-Section Of Relief Valve





(3) Nut (4) Screw

3. If the pressure setting is not correct, loosen jam nut (3) and turn clockwise to increase orcounterclockwise to decrease. One turn increases the setting approximately 430 kPa (63 psi).

NOTE: For shim adjustable relief valves, remove the cover and add shims. Each shim changes theopening pressure approximately 129 kPa (18.5 psi).

Test Of Control Valves (Speed And Direction)

Valves (1) and (3) give modulation for the rate of oil flow to the track motors. (See Speed And DirectionControl in Systems Operation).

Use the steps that follow to test the outlet pressures to the control valves for oil flow to the track motors.

1. Screw the plunger in on the track brake valve until the spool is blocked.

Control Valve For Speed And Direction

(1) Valve for control of movement in the REVERSE direction (2) Valve for control of steering (3) Valvefor control of movement in the FORWARD direction





Cross-Section Of Control Valve For Speed And Direction

(4) Plunger (5) Plunger (6) Shims (7) Shims

2. Install pressure gauges in the covers on the ends of the stems of the main control valves for trackmovement.

3. With the engine running, push plunger (4) of valve (1) down 7.9 mm (5/16 in.). The pressure at theinner (tang) end of the stems of the control valves for right track and left track movement must be 1200± 28 kPa (175 ± 4 psi). If the pressures are not the same, check the oil lines to the control valves forrestriction.

If the pilot pressure to the control valves is less than 1175 kPa (171 psi) or more than 1228 kpa (179 psi), make an adjustment by adding or removing shims (6).

Each 0.13 mm (.005 in.) shim will change the pressure of the pilot oil to the control valves 12 kPa (1.7 psi). Add shims to increase the pressure. Remove shims to decrease the pressure.

When plunger (4) is pushed down to its full travel, the oil pressure to the control valve must be 2300 ±170 kPa (335 ± 25 psi).

4. Do Step 3 again and use plunger (5), in valve (3), for oil pressure to the outer (spring) end of thestems of the control valves for right track and left track control. Use shims (7) to make adjustment of oil

pressure.

5. With plunger (4) pushed down to its full travel, move the hand lever for control of steering to the left,one half the distance of its full travel. The pressure of the oil to both ends of the spool for left track





5. Move the control lever for swing movement to the bumper spring for swing RIGHT position and holdit there.

6. Open bleed valve (7) one-half turn and make adjustment as needed to remove air from the housing.

7. Tighten bleed valve (7) when there is no more air in the oil flow from the bleed valve opening.

8. Move the control lever to NEUTRAL.

9. Do Steps 5, 6, 7 and 8 for swing LEFT using the bleed valve on the inboard end of the swing valve.[Opposite bleed valve (7)].

10. Do Steps 5, 6, 7 and 8 for bucket OPEN. Use the control lever for bucket movement and bleed valve(2).

11. Do steps 5, 6, 7 and 8 for bucket CLOSED. Use the control lever for bucket movement and the bleedvalve on the inboard end of the bucket valve. [Opposite bleed valve (2)].

12. Do Steps 5, 6, 7 and 8 for boom LOWER. Use the control lever for boom movement and bleed valve(1).

13. Do Steps 5, 6, 7 and 8 for stick OUT. Use the control lever for stick movement and bleed valves (4)and (5).

14. Do Steps 5, 6, 7 and 8 for boom RAISE. Use the control lever for boom movement and the bleedvalves on the inboard end of the boom valve and the boom crossover valve. [Opposite bleed valves (1)and (4)].

15. Do Steps 5, 6, 7 and 9 for stick IN. Use the control lever for stick movement and the bleed valve on

the inboard end of the stick valve. [Opposite bleed valve (5)].

16. Push down on the right pedal and hold. Do Step 6 and 7. Use bleed valves (3) and (6).

17. Push down on the left pedal and hold. Do Steps 6 and 7. Use bleed valves on the opposite end of theright and left track valves. [Opposite bleed valves (3) and (6)].

18. Turn the plunger on the track brake valve all the way out.

Adjustment Of Swing Relief Valve

1. Carefully open the cap on the filler tube for the hydraulic tank. Let any pressure in the tank out andtighten the cap.

2. Install a 0 to 41 500 kpa (0 to 6000 psi) pressure gauge in the pressure tap for the rear (swing) pump.

NOTE: Remove the plug with care because some oil will come out when it is removed.

3. Install the swing lock pin in the LOCKED position.

NOTE: If the pin does not drop into place, start the engine and move the swing control to the right or





left until it does.

4. Start the engine.

5. Get the temperature of the oil up to 49 to 65°C (120 to 150°F).

6. Move the swing control lever to the swing RIGHT position. Pressure must read 17 570 ± 1030 kPa(2550 ± 150 psi).

7. Move the swing control lever to the swing LEFT position. Pressure must read 17 570 ± 1030 kPa(2550 ± 150 psi).

8. Add or remove shims as necessary. Add shims to increase the pressure. Remove shims to decrease the pressure. Each 0.18 mm (.007 in.) shim will change the pressure setting 840 kPa (122 psi).

Pump Leakage

After the pump control tests are complete, it is known that the output of the pump of pilot system oil is

correct, the operation of the control valves for pump signal is correct, the relief valve in the pilot systemis set correct and operation of the servovalves is correct.

If the output of the piston pumps is not according to specifications, it is probable that there is too muchwear inside the pump. Because of pump design, leakage oil is routed through internal passages to the

pump supply.

Next to pump flow check, the best means of checking pump performance is through implement cycletimes.

REFERENCE: See Specifications For 225B & 229 Excavators Hydraulic System, Form No.

SENR3464, for cycle times.

Adjustment of Pilot Control Valve

If the shim adjustment under spring (2) is not correct, the modulating range for one or more of the eight pilot-controlled circuits will be reduced. This would result in reduced control of the implement(s).

The pilot control valve (1) is adjusted by means of shims (3). Install a 4150 kPa (600 psi) gauge in valve(1) in the outlet of the implement circuit to be tested. Slowly move the lever to the implement position

To avoid personal injury, the bucket must always be lowered tothe ground before service is started. Only move the pilot controlvalve lever to the position where the respective pilot circuit linehas been disconnected and the gauge installed in its place.





being tested until an initial pressure is observed on the pressure gauge. The pressure reading should be310 ± 35 kPa (45 ± 5 psi). If the pressure is too low, then shim (3) should be added under spring (2). Ifthe pressure is too high, then shim (3) should be removed from under spring (2). One shim increases ordecreases the pressure setting as follows:





Pilot Control Valve

(1) Pilot control valve (2) Spring (four) (3) Shim (four locations)

Adjustment Of Pump Rotary Group





Pump Rotary Group

(1) Port plate (2) Spacer (3) Cylinder barrel (4) Piston (5) Center pin (6) Compression springs (four) (7)Shaft/gear (8) Bearing assembly (20) Bearing assembly

Tools Needed:

Gauge Blocks (Use standard gauge block set)

8S2328 Dial Indicator

8T7773 Measuring Kit

8T9298 Handle As.

8T9297 Cover-Top

8T7775 Cylinder

8T9296 Plate-Bottom

8T7778 Spacer

8T9303 Ball

8T7776 Pin

6D3027 Bolt

8T9299 Insert-Lower





8T7774 Support

8T7777 Plate

8T9302 Spacer

8T9301 Insert-Upper

Measuring Kit (8T7773) (Particle Consists)

(9) Support (10) Cylinder (11) Spacer (12) Centering pin (13) Centering disc (14) Lifting screws

Each of the two pump rotary groups are divided into a mechanical drive group [shaft/gear (7) and bearings assemblies (8) and (20)] and a hydraulic group [barrel (3), port plate (1), pistons (4), center pin(5), compression springs (6) and spacer (2)].

To prevent damage to pumps and motors, it is very important that

the cases are filled with hydraulic oil at least to the fill port beforeoperation.





Pump Rotary Group

(2) Spacer (5) Center pin (8) Bearing assembly (11) Spacer (12) Centering pin (19) Shim (D) Dimensionneeded for play (E) (E) Play determined by spacer (2) (F) Dimension determined by shim (19)

Play (E) between spacer (2) and pin (5), in combination with compression springs (6), maintain correctlimit of separation between barrel (3) and port plate (1) (lift-off limitation). This limits leakage duringheavy, transient loading of the pump.

When servicing the hydraulic group, there are two critical dimensions. Dimension (D) is determined by

one of seven sizes of spacer (2). Dimension (F) is determined by one of five thicknesses of shim.

Adjustment Of Displacement Angle And Bearing Preload





Setup Of Dial Indicator

(9) Support (16) Gauge blocks

1. Place support (9) on a surface plate. Position gauge blocks (16) on the support to get dimension (F) of76.00 mm (2.992 in.). Position a dial indicator over the gauge blocks and zero indicator.





Measurement For Shim Thickness

(8) Bearing assembly (19) Shim

2. Position bearing assembly on support (9). Slide bearing assembly and support under dial indicator.Add shims (19) to get a reading on the indicator between 0.00 and -0.05 mm (.000 and -.002 in.).

Thickness of shims (19):

9T3376 . . . 2.7 mm (.106 in.)

9T3377 . . . 2.8 mm (.110 in.)

9T3378 . . . 2.9 mm (.114 in.)

9T3379 . . . 3.0 mm (.118 in.)

9T3380 . . . 3.1 mm (.122 in.)





Stub Shaft Group

(8) Bearing assembly (19) Shim (20) Shaft (21) Bearing assembly (22) Nut

NOTE: The following adjustment procedure for bearing preload applies only to new bearings with themanufacturer's lubricant.

3. Install bearing assembly (8) with shims (19) identified in Step 2 on shaft (20). Install bearingassembly (21). Apply 9S3263 Thread Lock to nut (22).

4. For correct bearing preload, turn shaft (20) while tightening nut (22).

Shaft running torque . . . 3.5 to 4.0 N·m (31.00 to 35.40 lb.in.)

Lift-Off Limitation (Cylinder Barrel To Port Plate Maximum Separation)






(9) Support (16) Gauge blocks

1. Place support (9) on a surface plate. Position gauge blocks (16) on the support to get a dimension (D)of 127 mm (5 in.). Position a dial indicator over the gauge blocks and zero.





Installing Spacer

(2) Spacer (3) Cylinder barrel (11) Spacer (tooling) (17) Wire (18) Cylinder

2. Using a piece of wire (17), guide the spacer (2) (minimum thickness) into center pin cylinder (18) of barrel (3). Place spacer (11) and center pin (5) in the cylinder. Position the measuring kit cylinder (10)over support (9) and lay cylinder on its side. Carefully insert center pin and barrel into cylinder andreturn to the vertical position. Align the port plate (1) over the cylinder barrel (3) and insert centering

pin (12). Position centering disc (13) [with two lifting screws (14)] over the centering pin (12).





Positioning Of Barrel Assembly In Cylinder

Measurement For Spacer Thickness

(1) Port plate (2) Spacer (3) Cylinder barrel (5) Center pin (9) Support (10) Cylinder (11) Spacer (12)Centering pin (13) Centering disc (14) Lifting screws

3. Slide the above assembly under the dial indicator. The dial indicator must read between +0.05 to -0.10mm (+.002 to -.004 in.). There are seven different sizes of spacers (2) to choose from to get the correctliftoff limitation. There is a minimum spacer size. Each succeeding size of spacer is 0.10 mm (.004 in.)thicker.





Depending on the dial indicator reading, the correct size of spacer can be selected.

For example, the dial indicator has a reading of -0.50 mm (-.020 in.). To get the 127 +0.05 -0.10 mmdimension, remove the spacer with the minimum thickness and replace with a spacer which is 0.40 mm(.016 in.) thicker than the minimum. The tolerance should now be -0.10 mm (.004 in.).

Measurement For Spacer Thickness

4. Once the correct spacer size has been determined, the centering pin (12) and spacer (11) can beremoved and four compression springs (6) inserted using a straight piece of wire (17) as a guide.

Installation Of Compression Springs

(6) Compression springs (four) (17) Wire





Adjustment Of Motor Rotary Group (225B)

Motor Rotary Group

(1) Port plate (2) Cylinder barrel (3) Spacer (4) Center pin (5) Compression springs (four) (6) Piston(seven) (7) Shaft (8) Bearings (9) Shims (10) Cover assembly (11) Ring

Tools Needed:

Gauge Blocks


8T7760 Measuring Kit

8T9249 Handle As.

8T9248 Cover-Top

8T7764 Cylinder

8T9247 Plate-Bottom

8T7754 Support

8T7756 Support

8T9250 Spacer





8T9251 Insert-Lower

8T9272 Ball

8T9273 Ball

8T9274 Ball

8T7757 Plate

8T7759 Plate

8T7761 Pin

8T7763 Pin

6D3027 Bolt

8T9252 Insert-Upper

The motor rotary group is divided into a mechanical drive group [shaft (7), bearings (8) and cover (10)]and a hydraulic group [barrel (2), port plate (1), spacer (3), compression springs (5), pistons (6) andcenter pin (4)].

If parts of the motor are serviced, there are two critical dimensions which should be checked inassembling the motor rotary group. Shims (9) on the mechanical drive group and one of four spacers (3)on the hydraulic group are used to get these respective dimensions.

Use the following chart for adjustment dimensions in servicing the rotary group.





Dimensions For Adjustment

(12) Centering pin (tooling) (A) Distance from ring (11) to shaft (7) (B) Distance from shaft (7) tocentering pin (12) (C) Play [spacer (3) to center pin (4)]

Bearing Preload For Shaft Group

Shaft Group





(26) Nut (27) Shaft

NOTE: The following adjustment procedure for bearing preload applies only to new bearings with themanufacturer's lubricant.

1. Apply 9S3263 Thread Lock to nut (26).

2. For correct bearing preload, turn shaft (27) while tightening nut (26).

Shaft running torque . . . 1.1 to 1.5 N·m (10 to 13 lb in)

Adjustment of 40° Displacement Angle

This shim adjustment is necessary to maintain an exact angle between the center lines of drive shaft (7)and center pin (4). In turn, this maintains the proper alignment between the barrel (2) and its pistons (6).


(13) Gauge blocks (14) Support

1. Place support (14) on a surface plate. Position the gauge blocks (13) on the support to get dimension(A). Set the indicator in position over the gauge blocks and zero the dial.





Measurement For Shim Thickness

(14) Support (15) Cover (16) Ring location (17) Shims (18) Boss2. Position the mechanical drive group on support (14) so that boss (18) is located over the hole in thesupport. Place cover (15) (without the seal and O-ring) on the drive group. Do not install the ring atlocation (16). Slide drive group and support under the dial indicator. Add shims (17) to get a reading onthe indicator between 0 and -0.10 mm (-.004 in.).





Mechanical Drive Group

(15) Cover (17) Shims

Adjustment Of Lift-Off Limitation (Cylinder Barrel To Port Plate Maximum Separation)

Spacer (3) to pin (4) clearance in combination with the compression springs (5) maintain the correct barrel (2) to port plate (1) maximum separation. This maximum separation limits leakage during start up

and downhill operation.

This adjustment procedure determines the correct size of spacer to get the distance (B) between thecenter pin (center of pivot head) and centering pin (12). With the correct distance (B), clearance (C)

between spacer (3) and center pin (4) will be 0.10 to 0.25 mm (.004 to .010 in.).






(13) Gauge blocks (19) Support

1. Place support (19) on a surface plate. Using gauge blocks (13), build up the dimension (B) as listed inthe above chart. Set up the dial indicator and zero.





Installation Of Spacer

(1) Port plate (2) Cylinder barrel (3) Spacer (20) Wire (21) Cylinder

2. Using a piece of wire (20), guide the spacer (3) (minimum thickness) into center pin cylinder (21) of barrel (2). Place center pin in cylinder (21) without compression springs (5).

To avoid damage to center pin (4) and support (19) in the next step,place measuring kit cylinder (24) over support and lay cylinder onits side (horizontal).





For example, the tolerance for dimension (B) is -0.40 mm (-.016 in.) on the dial indicator. In this case,remove the spacer with the minimum thickness and replace with a spacer that increases the indicatorreading by 0.20 mm (.008 in.). This will give a dimension B reading in tolerance.

4. Once the correct spacer has been selected, the center pin (4) can be removed. The four compressionsprings (5) can then be inserted using a piece of wire (20) as a guide.

Installation Of Compression Springs

(5) Compression springs (20) Wire

Adjustment of Motor Rotary Group (229)





Motor Rotary Group

(1) Bearing (2) Shaft (3) Pin (pivot) (4) Spring (5) Barrel (6) Disc (7) Shims (8) Pistons (9) Spacers (10)Port plate

24° Displacement Angle

Tools Needed:


Gauge Blocks

(1) Bearing (2) Shaft (11) Ring (12) Gauge blocks (13) Gauge blocks

Dimension (B) is necessary to maintain an exact angle between the center lines of drive shaft (2) andcenter pin (3). Shims (7) are used to get Dimension (B) and maintain the proper alignment between

barrel (10) and its pistons (8).





Place assembled shaft (2) and bearing assembly (1) on two gauge blocks (12). Blocks (12) should be ona level surface such as a surface plate. They should be positioned so that the 19.05 mm (.75 in.)dimension is the height.

Put outer race (11) on shaft and bearing assembly and rotate to seat. Put together gauge blocks (13)totaling 110.05 mm (4.333 in.). Use the dial indicator and measure from the gauge blocks to the bearingrace. The difference between the two readings is the thickness of shim (7) to use when the flange isinstalled. To get the correct distance (B), use a combination of the following shims (7):

4T4497 . . . 0.50 mm (.020 in.)

4T4498 . . . 0.30 mm (.012 in.)

4T4499 . . . 0.10 mm (.004 in.)

Lift-Off Limitation (Cylinder Barrel To Port Plate Maximum Separation)

Tools Needed:

1U5472 Adjusting Plate Group

Depth Micrometer

(10) Plate (port) (14) Adjusting plate group (15) Micrometer (depth)

Spacer (9) to pin (3) clearance in combination with the compression spring (4) maintains the correct barrel (5) to port plate (10) maximum separation. This maximum separation limits leakage during startup and downhill operation.

This adjustment procedure determines the correct size of spacer to get clearance (A) between spacer (9)and center pin (3). Clearance (A) should be 0.15 ± 0.05 mm (.006 ± .002 in.).

1. Position the control plate (10) on the cylinder block. Install adjusting plate group (14). With a depthmicrometer (15), measure the depth to plate (10) through the hole in plate (14).

2. Use the center bolt of adjusting plate group (14) to push the control plate and cylinder block down.Again measure the depth to plate (10). The difference between the two measurements is the correct


bo cat retor excavadora225b

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