Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Knuckleboom Loader

2384C (S/N: KB61-UP; KAW1-UP)

2384D (S/N: KP51-UP; KBF1-UP)

2484C (S/N: KB71-UP; KAZ1-UP)

2484D (S/N: KP71-UP; KBR1-UP)

559C (S/N: KB41-UP; KAS1-UP)

559D (S/N: KL51-UP; KBL1-UP)

579C (S/N: KB51-UP; KAX1-UP)

579D (S/N: KL71-UP; KBA1-UP)

Introduction

© 2017 Caterpillar All Rights Reserved. This guideline is for the use of Cat 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 technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS Web) interface.

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	g01063311
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	g01063312
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	g01063314
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01093468
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	g01063316
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

Port Locations

Illustration 7	g03888777
Typical port locations and adjustments for tandem pumps (49) Ports for the negative flow control pressure (50) Adjustment screws for negative flow control (51) Adjustment screws for torque control (52) Discharge Ports (53) Gauge port for power shift pressure (54) Port for power shift pressure (55) Gauge ports for discharge pressure (57) Case drain ports (58) Suction port (59) Pilot pump discharge port (60) Electrical connector for solenoid (69) Adjustment screws for minimum displacement (70) Adjustment screws for high-pressure cut (71) Adjustment screws for maximum displacement (72) Gauge port for pilot pump pressure (73) Suction port for pilot pump

Illustration 8	g03328060
Hydraulic Schematic (49) Ports for the negative flow control pressure (50) Adjustment screws for negative flow control (51) Adjustment screws for torque control (52) Discharge Ports (53) Gauge port for power shift pressure (54) Port for power shift pressure (55) Gauge ports for discharge pressure (57) Case drain ports (58) Suction port (59) Pilot pump discharge port (70) Adjustment screws for high-pressure cut (72) Gauge port for pilot pump pressure (73) Suction port for pilot pump

1U-6392 Pressure Reducing Valve

Illustration 9	g01419112
1U-6392 Pressure Reducing Valve

Illustration 10	g01419113
1U-6392 Pressure Reducing Valve

Illustration 11	g01419118
1U-6392 Pressure Reducing Valve Schematic (61) Adjustment screw for the outlet pressure (62) Drain port (63) Gauge port for the inlet pressure (64) Port for the outlet pressure (65) Gauge port for the outlet pressure (66) Port for the inlet pressure

Pump Setup

Note: A power supply is required to operate the solenoid. The power supply should be capable of delivering 0 mA to 1.5 A with an infinite setting in that range.

1. Install quick disconnect fittings in the following ports.

   • (49) Both ports for the negative flow control

   • (53) Gauge ports for power shift pressure

   • (54) Port for power shift pressure

   • (55) or (56) Gauge ports for discharge pressure

2. Connect the suction port (58) to the test bench oil supply. Purge all air from the suction line. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction hose.

3. Connect both discharge ports (52) to the flow meter inlets on the test bench. Direct flow meter outlets to sump.

4. Connect the pilot pump discharge port (59) to a tee fitting with 8T-0856 Pressure Gauge attached. Connect the other end of the tee fitting to 9U-5841 Needle Valve. Connect 8T-0454 In-line Flow Meter inlet to the Needle Valve. Direct the flow meter output back to sump.

5. Refer to Illustration 11 to set up Step 5. Connect 1U-6392 Pressure Reducing Valve port for inlet pressure (66) to gauge port for discharge pressure (55). Connect port for outlet pressure (64) to the port for power shift pressure (54). Vent drain port (62) to atmosphere. Connect a 8T-0856 Pressure Gauge to gauge port for outlet pressure (65). Connect a 8T-0860 Pressure Gauge to gauge port for inlet pressure (63). Connect a 8T-0855 Pressure Gauge to the power shift gauge port (53).

6. Vent both negative flow control ports (49) to atmosphere. Connect a power supply to the electrical connector for solenoid (60).

7. Fill the pump case with oil. Pour oil directly into case drain port (57) until the case is full. Direct a line from case drain port (57) to the test bench reservoir.

8. 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.

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)

Illustration 12	g01206428
Torque control characteristics (Q) Discharge flow (P) Discharge pressure

1. Start rotating the pump according to Step 1 of the Test Specifications. Listen for abnormal noise. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around the control valve. Verify flow from the pump.

   Run the pump for at least 5 minutes to raise the temperature of the oil and purge the system of air.

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   Illustration 13	g01419149
   Hydraulic schematic for maximum displacement and torque control characteristics setup (49) Ports for negative flow control pressure (53) Gauge port for power shift pressure (54) Port for powershift pressure (55) Gauge port for discharge pressure (61) Adjustment screw for the outlet pressure (62) Outlet port to tank (63) Gauge port for the inlet pressure (64) Port for the outlet pressure (65) Gauge port for the outlet pressure (66) Port for the inlet pressure

2. Step 2 will verify maximum displacement and torque control characteristics. Both pumps will be tested at the same time. Compare the flow rates at each step to the values in Steps 2.a through 2.d in the Test Specifications. Refer to Illustration 12 for the constant horsepower curve. Step 2.b will also verify the discharge flow of the pilot pump.

   1. Slowly increase the input RPM. If the actual discharge flow is less than Step 2.a of the Test Specifications, the pump may not be mechanically feasible.

   2. Slowly increase the discharge pressure for both main pumps to the value in Step 2.b of the Test Specifications. Cycle the discharge pressure to verify the destroke point. Adjust the adjustment screw for the 1U-6392 Pressure Reducing Valve until the outlet pressure (65) is equal to the power shift pressure value in Step 2.b through 2.d of the Test Specifications. Slowly increase the signal current from power supply until the pressure at the power shift gauge port (53) is adjusted according to Steps 2.b through 2.d of the Test Specifications. The discharge flow should drop as the discharge pressure increases. The pumps should now be under constant horsepower control.

      Slowly increase the discharge pressure for the pilot pump to the value in Step 2.b of the Test Specifications. Compare the actual flow rate with the value in Step 2.b of the Test Specifications.

   3. Decrease the pilot pump pressure to zero. Slowly increase the discharge pressure to the main pumps to the value in Step 2.c of the Test Specifications. Compare the actual flow rates with the value in Step 2.c of the Test Specifications.
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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 during adjustment of the high pressure relief valve if recommended hose maintenance practices are not followed. Escaping fluid under pressure can penetrate body tissue causing serious injury, and possible death. Adjustment of the high pressure cut or pressure override valve shall only be performed when the pump is operating at a zero discharge pressure condition. Continuation of the pump test procedure can be resumed when this high pressure adjustment is completed.

   4. Slowly increase the discharge pressure for the pumps to the value in Step 2.d of the Test Specifications. Compare the actual flow rates with the value in Step 2.d of the Test Specifications.

      Note: The pump torque control must be adjusted if Steps 2.b through 2.d flow values are not within test specifications. Turn adjustment screw for torque control (51) accordingly.

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   Illustration 14	g01181511
   Negative flow characteristics (Q) Discharge flow (R) Negative flow control pressure

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   Illustration 15	g01419153
   Hydraulic schematic for negative flow control setup (49) Ports for the negative flow control pressure (53) Gauge port for power shift pressure (54) Port for the power shift pressure (55) Gauge port for discharge pressure (61) Adjustment screw for the outlet pressure (62) Outlet port to tank (63) Gauge port for the inlet pressure (64) Port for the outlet pressure (65) Gauge port for the outlet pressure (66) Port for the inlet pressure (67) 006-0210 Tee

3. Steps 3.a and 3.b verify the operation of the negative flow control. Both pumps will be tested at the same time. 1U-6392 Pressure Reducing Valve will be used to adjust the negative flow control pressure. Refer to Illustration 14 for an example of the negative flow control. Refer to Illustration 15 to set up the negative flow control.

   Decrease the input RPM and all pressures to zero. Decrease signal current from power supply to zero. Disconnect the 1U-6392 Pressure Reducing Valve outlet pressure (64) from the port for power shift pressure (54). Vent the port for power shift pressure (54) and the gauge port for power shift pressure (53) to atmosphere. A 006-0210 Tee will be required to connect 1U-6392 Pressure Reducing Valve outlet pressure (64) to the negative flow control ports (49).

   1. Increase the input RPM and the discharge pressure to both pump discharge ports (52) according to Step 3.a of the test specifications. Adjust the adjustment screw (61) for the 1U-6392 Pressure Reducing Valve until the outlet pressure (65) is equal to the negative flow control pressure (49) in Step 3.a of the Test Specifications. Increase the negative flow control pressure until the flow begins to decrease. This is the destroke point. The pumps should now be under negative flow control. Slowly cycle the negative flow control pressure to both pumps around the value in Step 3.a of the Test Specifications. This is accomplished to verify the destroke point. The discharge flow should drop as the negative flow control pressure increases.

      If either pump begins to destroke too soon, then the negative flow control valve should be disassembled and inspected. If either pump begins to destroke too late, then the negative flow control valve should be disassembled and inspected.

   2. Slowly increase the negative flow control pressure (49) according to Step 3.b of the Test Specifications. The pumps should be fully destroked.
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   Illustration 16	g01419197
   Hydraulic schematic for pump efficiency setup (49) Port for negative flow control pressures (53) Gauge port for power shift pressure (54) Port for power shift pressure (55) Gauge port for discharge pressure (68) Signal pressure from test bench

4. Steps 4.a and 4.b measure the amount of internal leakage. Only one pump will be tested at a time. The pump not being tested will be put into standby. Refer to Illustration 16 to set up the pump efficiency.

   Decrease the input RPM and all pressures to zero. Disconnect 006-0210 Tee. Vent negative flow control port (49) on the pump to be tested to atmosphere. Disconnect 1U-6392 Pressure Reducing Valve from the pump. Connect gauge port for discharge pressure (55) or (56) to negative flow control port (49) on the pump to be put in standby. Connect the signal pressure from the test bench to the port for the power shift pressure (54). Connect 8T-0855 Pressure Gauge to the power shift gauge port (53).

   1. Start rotating the pump according to Step 4.a of the Test Specifications. Slowly increase the signal current until the pressure at the power shift gauge port (53) is adjusted according to Step 4.a of the Test Specifications. Slowly increase the discharge pressure to the pump that is not being tested to the standby pressure in the test specifications. The pump should be fully destroked and in standby. Record flow of pump being tested.

   2. Slowly increase the discharge pressure to the tested pump to the value in Step 4.b of the Test Specifications. Subtract the actual discharge flow rate measured in Step 4.b from the actual discharge flow recorded in Step 4.a. This is the internal leakage. The internal leakage should not exceed the value in Step 4.b of the Test Specifications. The pump may not be mechanically feasible if the internal leakage is too high. The pump should be disassembled and inspected. Repeat Step 4 to test the pump that was in standby.

5. Step 5 will verify operation of the high-pressure cut for pumps equipped with high-pressure cut. Leave connections as used in Step 4 of the Test Procedure. Only one pump will be tested at a time. The pump not being tested will be put into standby. Refer to Illustration 16 for setup.

   Start rotating the pump according to Step 5 of the Test Specifications. Slowly increase the signal current until the pressure at the power shift gauge port (53) is adjusted according to Step 5 of the test specifications. Slowly increase the discharge pressure to the pump that is not being tested to the standby pressure in the test specifications. The pump in standby should be fully destroked and in standby. Slowly increase the discharge pressure to the tested pump to the value in Step 5 of the Test Specifications. The pump being tested should destroke at this pressure to the discharge flow value in 5 of the Test Specifications. If the pump does not destroke at this pressure, adjust high-pressure cut accordingly. Repeat Step 5 to test the pump that was in standby.

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

Reduce RPM and all pressures to zero. Remove the component from the test bench. Drain the oil from the pump. Plug all of the ports.

Test Specifications

Test Bench Tooling