Bench Test Procedure for Hydraulic Piston Pumps {0374, 0599, 0721, 0738, 3108, 4350, 5070} Caterpillar

Telehandler

TH306D (S/N: TD21-UP; TD31-UP)

TH3510D (S/N: TH21-UP; TH31-UP)

Introduction

© 2016 Caterpillar All Rights Reserved. This guideline is for the use of Caterpillar Dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This Special Instruction includes test procedures for piston pumps. This Special Instruction also provides specifications. The technician should have a good understanding of hydraulic piston pumps. The technician should be educated in the operation of the hydraulic test bench. The test benches in this document are available through the Caterpillar Service Tool Division. Gather all necessary tooling before you need to hook up the pump. Some of the required tooling appears in a table at the end of this document. There are many possible variations of tooling that could be used. Not every possible variation can be listed.

For questions or additional information concerning this guideline, submit a feedback form in the Service Information System website. To address an urgent need, please use the following to relay your request to Caterpillar Repair Process Engineering:

• Cat Dealer Technical Communicator

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Canceled Part Numbers and Replaced Part Numbers

This document may not include all Canceled part numbers and replaced part numbers. Use NPR on SIS for information about Canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Safety

Illustration 1	g02139237

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Personal injury or death can result from improperly checking for a leak. Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.

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Pump test pressures in this guideline may exceed the normal operating range of the hydraulic test hoses utilized when connecting the tested pump to the test bench. However, the order of magnitude of these pressures is significantly below the burst strength of the Caterpillar "XT6" product. High pressure oil can escape through improperly assembled hoses and fittings. High pressure oil can also escape through poorly maintained hoses and fittings. High pressure oil may also leak through hose that has become damaged over the life of the hose due to the pressure levels that occur during test bench operation. Personal injury or death can result from improper hose & fitting inspection or improper hose replacement procedures. Escaping fluid under pressure can penetrate body tissue causing serious injury, and possible death. Thoroughly inspect all testing hoses, fittings, and quick disconnects prior to any testing operation. Check the assembly date tag or hose assembly log date for a hose life indicator. Replace all Test Bench hoses at a minimum of every 2 years or earlier if the hose or fittings appear to be damaged.

Summary

This procedure is specific to the type of pump and the type of control. Refer to the test specifications and the tooling at the end of this document.

Note: A paper copy of this document may not be the latest version. Go to the Service Information System (SIS) to view the latest version.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 2	g01140178
Connections for the test center (1) Flow control for discharge (2) F3 Flow meter inlet (3) F4 Flow meter inlet (4) Oil supply from the auxiliary pump (5) F3 inlet for the flow meter with flow limiter (6) F3 outlet for the flow meter with pressure control (7) Load sensing pressure (8) Signal pressure (9) F4 outlet for the flow meter (10) Return to tank (11) Connections for case drain (12) Oil supply

Illustration 3	g01140179
Control and gauges for the test center (13) Meter for speed and torque (14) Gauge for signal pressure (15) Control for signal pressure (16) Pressure gauge for auxiliary pump (17) Auxiliary pump flow (18) F3 discharge pressure gauge (19) F3 discharge flow (20) F4 discharge pressure gauge (21) F4 discharge flow (22) Auxiliary pump flow control (23) F3 margin pressure (24) F3 Load control for discharge pressure (25) F4 Load control for discharge pressure

Connections for the Caterpillar Hydraulic Test Bench

Illustration 4	g01140180
Connections for the test bench (26) Flow meter 1 loop and flow meter 2 loop (27) Oil supply

Illustration 5	g01140183
Connections for the Test Bench (28) Flow meter 2 loop (29) Flow meter 1 loop (30) Flow meter 2 outlet (31) Signal pressure line (32) Flow meter 2 inlet (33a) Flow meter 1 outlet (33b) Auxiliary oil supply outlet (34) Auxiliary oil supply inlet (35) "Flow meter 1" inlet

Illustration 6	g01140185
Control and gauges for the test bench (36) Auxiliary oil supply pressure (37) Signal pressure (38) Control for signal pressure (39) Flow meter 1 discharge pressure (40) Control for auxiliary oil supply pressure (41) Flow meter 2 discharge pressure (42) Auxiliary oil supply control (43) Flow meter 2 discharge flow (44) Discharge flow for auxiliary pump (45) Flow meter 1 discharge flow (46) Flow meter 1 load control (47) Speed and direction control (48) Flow meter 2 load control

Pump Illustrations

Illustration 7	g06063259
Port locations and adjustments. (49) Swashplate position sensor (50) Air purge port (51) Gauge port for stroking pressure (52) Electrical connector for pump stroking (53) Gauge port for high pressure (54) Electrical connector for pump stroking (55) Adjustment screw for pressure cutoff (56) Gauge port for stroking pressure (57) Adjustment screw for mechanical zero (58) Gauge port for stroking pressure (59) Adjustment screw for crossover relief (60) Gauge port for pilot pressure (61) Hydrostatic bypass adjustment (62) Gauge port for charge pressure (63) Suction port (64) Adjustment screw for crossover relief (65) Gauge port for charge pressure (66) Adjustment screw for charge pressure relief (67) Case drain port (68) Discharge port (69) Gauge port for discharge pressure (70) Gauge port for stroking pressure (71) Case drain port (72) Gauge port for discharge pressure (73) Discharge port (74) Charge oil outlet (to filter) (75) Charge oil return (from filter)

Illustration 8	g06064423
Hydraulic schematic (49) Swashplate position sensor (50) Air purge port (51) Gauge port for stroking pressure (52) Electrical connector for pump stroking (53) Gauge port for high pressure (54) Electrical connector for pump stroking (55) Adjustment screw for pressure cutoff (56) Gauge port for stroking pressure (57) Adjustment screw for mechanical zero (59) Adjustment screw for crossover relief (60) Gauge port for pilot pressure (61) Hydrostatic bypass adjustment (62) Gauge port for charge pressure (63) Suction port (64) Adjustment screw for crossover relief (65) Gauge port for charge pressure (66) Adjustment screw for charge pressure relief (67) Case drain port (68) Discharge port (69) Gauge port for discharge pressure (71) Case drain port (72) Gauge port for discharge pressure (73) Discharge port (74) Charge oil outlet (to filter) (75) Charge oil return (from filter)

9U-5902 Rectifier Block

Illustration 9	g06064428
9U-5902 Rectifier Block Connections (76) High-pressure port (77) High-pressure outlet (78) High-pressure port (79) Low-pressure inlet

Illustration 10	g06064432
9U-5902 Rectifier Block Schematic (76) High-pressure port (77) High-pressure outlet (78) High-pressure port (79) Low-pressure inlet

9U-5893 Heat Exchanger

Illustration 11	g06065006
9U-5893 Heat Exchanger Connections (80) Inlet from flow meter loop (81) Outlet "to rectifier block" (82) Water inlet (83) Water outlet

198–4240

Illustration 12	g06065139
198–4240 Electric Pressure Gauge Group Connections (84) Pressure gauge (85) Red transducer 34500 kPa (5000 psi) (86) Blue transducer 3450 kPa (500 psi)

Pump Setup

Note: A power supply is required to operate the solenoids on this pump. The power supply should have capability of delivering 0 mA to 1200 mA with an infinite setting in that range.

1. Mount the pump onto the test bench with air purge port (50) facing up. Connect the drive line from the test bench to the drive shaft on the pump.

2. Install pressure taps in the following test ports:

   (51) Gauge port for stroking pressure

   (56) Gauge port for stroking pressure

   (69) Gauge port for discharge pressure

   (72) Gauge port for discharge pressure

3. Connect suction port (63) to the test bench oil supply. Also connect charge oil outlet (74) to charge oil return (75).

4. Purge all air from the suction line. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction hose.

5. Connect pump discharge ports (68) and (73) to the 9U-5902 Rectifier Block high-pressure ports (76) and (78).

6. Connect the 9U-5902 Rectifier Block outlet (77) to the flow meter inlet on the test bench.

7. Connect the flow meter outlet to the 9U-5398 Heat Exchanger inlet (80) .

8. Connect the 9U-5893 Heat Exchanger outlet (81) to the low-pressure return (79) on the 9U-5902 Rectifier Block.

9. Connect 8T-0861 Pressure Gauges to the gauge ports for discharge pressure (69) and (72) .

10. Fill the pump case with oil. Pour oil directly into case drain port (67) until the case is full. Direct flow from case drain port (67) to test bench reservoir.

11. Connect a power supply to the electrical connector for stroking solenoid (52) or (54).

12. Connect a multimeter to the swashplate position sensor (49).

    Note: Refer to the "Swashplate Position Sensor Setup" section of this document.

13. Do not rotate the pump in the wrong direction. The correct direction of rotation will be stated on the pump. The correct direction of rotation will also be in the Test Specifications. The direction of rotation is viewed from the input shaft end. Visually check the pump for proper rotation.

Swashplate Position Sensor Setup

Illustration 13	g06070214
146-4080 Digital Multimeter Gp (87) Common port (88) Voltage port

Illustration 14	g06070233
276-7273 Sensor Test Box (Position Sensor) (89) Positive voltage banana connector (90) Negative voltage banana connector (91) Four-pin Deutsch connector (92) Battery test momentary switch

Illustration 15	g06070239
Fabricated electrical adapter (93) Four-pin Deutsch connector (94) Three-pin Deutsch connector

Illustration 16	g06070246
Schematic of swash plate position sensing setup (49) Swashplate position sensor (89) Positive voltage banana connector (90) Negative voltage banana connector (91) Four-pin Deutsch connector (92) Battery test momentary switch (93) Four-pin Deutsch connector (94) Three-pin Deutsch connector

1. Connect 276-7273 Sensor Test Box to 146-4080 Digital Multimeter Gp. Insert positive voltage banana connector (89) into voltage port (88) and negative voltage banana connector (90) into common port (87).

   Note: Use an electrical adapter to connect 276-7273 Sensor Test Box to the swashplate position sensor (49) on the pump. To fabricate this adapter, refer to Illustration 16 for the schematic.

2. Connect four-pin Deutsch connector (91) into four-pin Deutsch connector (93).

3. Connect three-pin Deutsch connector (94) to the swashplate position sensor (49).

4. Turn on 146-4080 Digital Multimeter Gp to read DC voltage. The battery power of the 276-7273 Sensor Test Box can be checked by holding in the battery test momentary switch (92) when the multimeter is on.

Adjustment for Mechanical Zero Position

1. Start rotating the pump at the value in Step 1 of the Test Specifications. Be sure to sustain oil flow to port (63) in Steps 1 through 5 of the Adjustment for Mechanical Zero. Vent the ports for the stroking pressure (51) and (56) to the atmosphere. This will equalize the pressure on the servo spool. Install pressure gauges on ports (69) and (72). Turn the load control on the test bench completelyclockwise to control the pump discharge pressure. If the mechanical zero adjustment is incorrect, a discharge pressure higher than the charge pressure may occur.

2. Turn the adjustment screw for the mechanical zero (57) clockwise. Continue to turn until a pressure of 200 psi above charge pressure is achieved. This pressure may be seen on the gauge port for the system pressure B (69) or gauge port for the system pressure A (72). Mark the position of the adjustment screw for the mechanical centering (57).

3. Turn adjustment screw for the mechanical centering (57) counterclockwise until pressure increases on gauge ports (69) or (72). Mark the position of the adjustment screw for the mechanical centering (57).

4. A mark should be placed halfway between position one and position two. Turn the adjustment screw for the mechanical centering (57) to the midpoint of both marks. There should be less than a 34.5 kPa (5 psi) pressure differential between pump gauge ports (69) and (72).

5. Stop rotating the pump. Turn the load control on the test bench for pump discharge pressure counterclockwise. Allow the discharge pressure of the pump to decrease. Plug or install pressure gauges on gauge ports for stroking pressure (51) and (56).

Test Procedure

Note: The steps in the procedure correlate with the steps under the Test Specifications according to your specific part number.

The contamination level of the hydraulic oil in the test bench should be ISO 16/13 or better. The oil in the test bench should be one of the following.

• SAE 10W at 50 °C (122 °F) or

• Mobil DTE-11 at 46 °C (115 °F)

1. This step will verify correct pump setup and allow oil to warm.

   Start rotating the pump according to the RPM in Step 1 of the Test Specifications. Verify the flow rates and listen for abnormal noise. Verify that all connections are secure. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around control valves. Check the gauge port for the charge pressure (65). Compare the actual charge pressure with the value in Step 1 of the Test Specifications. If the charge pressure is not within the Test Specifications adjust the charge relief valve. Adjust the charge relief valve by turning the adjustment screw (66) clockwise or counterclockwise accordingly. Run the pump for at least five minutes to raise the temperature of the oil and purge the system of air.

2. This step will verify the function of the swashplate position sensor.

   Slowly increase input speed to the value given in Step 2 of the Test Specifications. Verify correct voltage from the swashplate position sensor (49) according to Step 2 of the Test Specifications.

   Note: The pump has two separate solenoids. Test one solenoid at a time. Repeat steps 3 through 7 of the Test Procedure to test the other solenoid.

3. This step will verify the beginning of the control range.

   Increase the signal current to solenoid (52) or (54) according to the value in Step 3 of the Test Specifications. This is the point of upstroke of the pump. The pump operation or the control of the signal pressure may not be operating properly if the actual discharge flow is not correct.

   Note: Some flow meters may not be able to read discharge flows at this low level. Slowly increase signal current to a value that is higher than the value in Step 3 of the Test Specifications if the flow meter does not register the flow. Continue until the flow begins to register.

4. This step will verify the end of the control range and function of the swashplate position sensor.

   Increase the signal current to (52) or (54) to the value in Step 4 of the Test Specifications. The pump should be fully upstroked. Record actual pump flow. The pump or the control for the proportional solenoid valve may not be mechanically feasible if the actual flow is not equal to the value in Step 4 of the Test Specifications.

   Verify correct voltage from the swashplate position sensor (49) according to Step 4 of the Test Specifications.

5. This step will verify pump efficiency.

   Increase pump discharge pressure to the value in Step 5 of the Test Specifications. Measure pump leakage. Calculate the total loss. The pump may not be mechanically feasible if the total loss is higher than the allowable value in Step 5 of the Test Specifications.

   Subtract the discharge flow that was recorded in Step 5 of the Test Procedure from the discharge flow that was recorded in Step 4 of the Test Procedure to find the total loss.

   Example: Step 4 flow 162 L/min (42.8 US gpm) - "Step 5 flow" 158 L/min (41.7 US gpm) = "total loss" 4 L/min (1.1 US gpm). The "max. allowable loss" is 7.2 L/min (1.9 US gpm).

   The pump in the example is acceptable because the actual total loss is less than the maximum allowable loss.

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   NOTICE
   This step requires discharge pressures up to 50330 kPa (7300 psi). If you are using hoses or fittings that are not rated for this pressure it is unsafe to perform this portion of the test and you must skip this step.

   Note: Crossover relief valves may not be preset from factory. They must be set during component testing or once the component is installed on the machine.

6. This step will verify setting of the crossover relief valves. Only one crossover relief valve will be adjusted at a time dependent on which direction the pump is stroked.

   To attain high pressure, turn the adjustment screw for pressure cutoff (55) completely clockwise.

   Slowly increase discharge pressure to the value in Step 6 of the Test Specifications. Discharge flow should drop to zero. If discharge flow does not drop to zero, adjust the crossover relief valve. Adjust the crossover relief valve by turning the adjustment screw for crossover relief (59) or (64) clockwise or counterclockwise accordingly.

   Once the crossover relief valve has been adjusted, slowly reduce discharge pressure to the value in Step 5 of the Test Specifications.

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   NOTICE
   This step requires discharge pressures up to 46000 kPa (6670 psi). If you are using hoses or fittings that are not rated for this pressure, do not perform this portion of the test. Youmust skip this step.

7. This step will verify setting of the pressure cutoff valve.

   Slowly increase discharge pressure to the value in Step 7 of the Test Specifications. Discharge flow should drop to zero. If discharge flow does not drop to zero, adjust the pressure cutoff valve. Adjust the pressure cutoff valve by turning the adjustment screw for crossover relief (55) clockwise or counterclockwise accordingly.

Repeat Steps 3 through 7 of the Test Procedure and apply current to the other electrical connector for pump stroking (52) or (54) to verify settings on both sides of the pump.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.

Once testing is complete reduce all pressures, speeds, and flow to zero. Allow the component to cool. Drain all oil from the component. Cap or plug all ports.

Test Specifications

Bench Test Tooling