Bench Test Procedure for Hydraulic Piston Pumps{5070} Caterpillar

Excavator:

320D (S/N: BWW1-UP)

Introduction

© 2012 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.

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 Dealer Service Tools. 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. In order to address an urgent need, use the following to relay your request to Caterpillar Repair Process Engineering:

• Cat Dealer Technical Communicator

• Dealer Solution Network

• Cat Technical Representative

• Knowledge Network (online)

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

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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. The test procedure should be used with the test specifications and tooling sections. Both sections are displayed toward the back of this document.

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

References

Connect for the Caterpillar Hydraulic Test Center

Illustration 1	g01581273
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 2	g01581274
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 3	g01581278
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 4	g01581279
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 5	g01581280
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 6	g01590072
Typical port locations and adjustment locations (49) Suction port (50) Discharge port (51) Case drain port (52) Adjustment screw for minimum displacement (53) Adjustment screw for high-pressure cut

Illustration 7	g01590637
Typical port locations and adjustment locations (54) Adjustment screw for maximum displacement (55) Case drain port

Illustration 8	g01625806

Pump Setup

1. Connect a 1 inch high pressure "XT-6" rated hose from the pump discharge port (50) to the flow meter inlet on the test bench.

2. Connect a 1 inch high pressure "XT-6" rated hose from the flow meter outlet on the test bench back to the tank.

3. Connect the oil supply suction hose to pump inlet port (49) .

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

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

6. Connect an in-line flow meter to the case drain port (51) or (55). Direct the oil from the in-line flow meter back to the tank.

7. Do not operate the pump in the wrong direction. The correct direction of rotation will be stated on the pump. The direction of rotation is viewed from the input shaft end. Visually check for proper rotation of the test bench.

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)

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Illustration 9	g01585522

1. Start rotating the pump according to the RPM listed in Step 1 of the "Test Specifications". Listen for abnormal noise and verify flow from the pump. Be sure all connects are secure and not leaking. Check for leaky shaft seals and control valve connections.

2. Slowly increase the input RPM to the value in Step 2 of the "Test Specifications". The adjustment screw for the maximum displacement (54) may need adjusted in order to achieve the correct discharge flow. The pump may not be feasible if the actual flow is less than the value in Step 2 of the "Test Specifications". The pump should be disassembled and inspected.

3. Increase the pump discharge pressure to the value in Step 3 of the ""Test Specifications" ". Compare the actual case drain value with the case drain value in Step 3 of the ""Test Specifications" ". This value is an indication of the pump efficiency. The pump may not be mechanically feasible if the case drain is more than the value Step 3 of the "Test Specifications". The pump should be disassembled and inspected.

4. Increase the pump discharge pressure to the value in Step 4 of the "Test Specifications". Turn the adjustment screw for the high pressure cut (53) until the actual high-pressure cut value is equal to the value in Step 4 of the "Test Specifications". Pump discharge flow should be zero when the pressure cut is reached.

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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 pressure to zero. Remove the component from the test bench. Drain the oil from the pump. Cap and plug all ports.

Test Specifications

Tooling