Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Load Haul Dump

R1700 (S/N: KT41-UP)

Wheel Loader

950M (S/N: NHL1-UP)

Introduction

© 2018 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

Pump Illustrations

Illustration 7	g06312154
Port locations and adjustments: (49) Adjustment screw for minimum displacement (50) Case drain port (51) Gauge port for discharge pressure (52) Servo assist port (53) Discharge port (54) Adjustment screw for maximum displacement (55) Adjustment screw for margin pressure setting (56) Pressure port for load sensing (57) Case drain port (58) Suction port

Illustration 8	g06312161
Port locations and adjustments: (50) Case drain port (51) Gauge port for discharge pressure (52) Servo assist port (53) Discharge port (55) Adjustment screw for margin pressure setting (56) Pressure port for load sensing (57) Case drain port (58) Suction port

4C-3582 4C-35824C-3582 4C-35824C-3582 4C-3582 4C-3582 Load Sensing Valve

Illustration 9	g01451543
4C-3582 Load Sensing Valve (59) Outlet port (60) Adjustment for the discharge flow (61) Inlet port (62) High-pressure port (63) Adjustment for the discharge pressure

Illustration 10	g01451546
4C-3582 Load Sensing Valve (60) Adjustment for the discharge flow (61) Inlet port (64) Low-pressure port (65) Pressure port for load sensing

Illustration 11	g01451549
Schematic for 4c-3582 Load Sensing Valve (59) Outlet port (60) Adjustment for the discharge flow (61) Inlet port (62) High-pressure port (63) Adjustment for the discharge pressure (64) Low-pressure port (65) Pressure port for load sensing

Illustration 12	g01451664
4C-3582 Load Sensing Valve and 1U-5796 Pressure Differential Gauge (59) Outlet port (60) Adjustment for the discharge flow (61) Inlet port (62) high-pressure valve port (63) Adjustment for the discharge pressure (64) low-pressure valve port (65) Pressure port for load sensing (66) Pressure differential gauge group (67) low-pressure gauge port (68) high-pressure gauge port

Pump Setup

1. Mount the pump with the control facing upward.

2. Connect a suction hose from the test bench oil supply to suction port (58) on the pump.

3. Connect a 1 inch high pressure "XT6" hose from the pump discharge port (53) to inlet port (61) on the 4C-3582 Load Sensing Valve.

4. Connect a 1 inch high pressure "XT6" hose from the outlet port (59) on the 4C-3582 Load Sensing Valve to the flow meter inlet on the test bench.

5. Connect a 1 inch high-pressure hose from the flow meter outlet on the test bench back to the tank.

6. Connect a 6D-7726 Hose Assembly to the pressure port for load sensing (65). Connect the other end of 6D-7726 Hose Assembly to the pressure port for load sensing (56) on the pump.

   Note: Do not use 1U-5754 Hose Assembly or 1U-5755 Hose Assembly for load sensing signal lines. The flow rate through these hoses will not compensate for the possible leakage through the control valve. Erratic readings will result.

7. Connect the 1U-5796 Pressure Differential Gauge Group (66) to the high-pressure valve port (62) and low-pressure valve port (64) on the 4C-3582 Load Sensing Valve. The port marked "hi" (68) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "hi" (62) on the 4C-3582 Load Sensing Valve. The port marked "low" (67) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "low" (64) on the 4C-3582 Load Sensing Valve.

   Note: The ports marked "low" (67) and "sense line" (65) on the 4C-3582 Load Sensing Valve are reading the same pressure.

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

9. Fill the pump case with oil. Pour oil directly into a case drain port until the case is full.

10. Connect an in-line flow meter to the case drain port (50). Direct the oil from the in-line flow meter back to the tank.

11. 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 Test 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)

Note: For Steps 1, 2, 4, and 5 be sure adjustment knob for discharge flow (60) and adjustment is completely backed out on the 4C-3582 Load Sensing Valve.For Step 1 be sure adjustment for the discharge pressure (63) is completely backed out on the 4C-3582 Load Sensing Valve.

1. This step will verify correct assembly of the pump.

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

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

2. This step will check the maximum displacement setting of the pump.

   Slowly increase the input RPM to the value in Step 2 of the Test Specifications. Slowly increase the discharge pressure to the value in Step 2 of the Test Specification. The Record the discharge flow. If the actual flow is less than the value in Step 2 of the Test Specifications turn the adjustment screw for maximum displacement (54) until discharge flow is within specification.

   Reduce discharge pressure to zero.

3. This step will check the minimum displacement setting of the pump.

   For this step only, vent pressure port for load sensing (56) to atmosphere.

   Increase discharge pressure to the value (reference only) in Step 3 of the Test Specifications. The pump may destroke before the specified discharge pressure is reached. Discharge flow should decrease to minimum according to Step 3 of the Test Specifications. If discharge flow is not within specification, turn the adjustment screw for minimum displacement (49) until the discharge flow is within specification.

   Reduce discharge pressure to zero. Reconnect the 6D-7726 Hose Assembly to the pressure port for load sensing (56) on the pump.

4. This step will check the margin pressure setting of the pump.

   Slowly increase discharge pressure to the value in Step 4 of the Test Specifications. The discharge flow is adjusted by using the 4C-3582 Load Sensing Valve. Bench circuitry will be used for flow limiting when using a 1U-9400 Test Center. Decrease the discharge flow according to the values in Step 4 of the Test Specifications. Adjust the discharge pressure according to the values in Step 4 of the Test Specifications. Turn the adjustment screw for margin pressure setting (55) to the value in Step 4 of the Test Specifications. The margin pressure will be displayed on the 1U-5796 Pressure Differential Gauge (66).

   Note: The margin pressure may change as discharge pressure changes. Adjust margin pressure at Step 4 within operating conditions only.

   Increase discharge flow to full flow by turning the adjustment for discharge flow (60) completely counter clockwise.

5. This step will check pump efficiency.

   Increase the pump discharge pressure to the value in Step 5 of the Test Specifications. Compare the actual values from the case drain with the values in Step 5 of the Test Specifications. This value is an indication of the pump efficiency. If the case drain flow is greater than the value given in Step 5 of the Test Specifications, the pump may not be mechanically feasible. The pump is to be internally inspected.

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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 all pressures, flows, and speeds to zero. Allow the component to cool. Drain the oil from the pump. Cap or plug all the ports. Remove the component from the test bench.

Test Specifications

Tooling