Bench Test Procedure for Hydraulic Piston Pumps{5070} Caterpillar

Excavator:

307C (S/N: BNE1-UP; BCM1-UP)

308C (S/N: KCX1-UP)

Mini Hydraulic Excavator:

303 (S/N: DMA1-2107)

303.5 (S/N: DCH1-UP; AFW1-UP)

304.5 (S/N: WAK1-UP; ANR1-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 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. 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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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.

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

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) in order to view the latest version.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 1	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 2	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 3	g01063314
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 4	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 5	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

This piston pump is produced with multiple types of housings. Port locations will vary. Match the correct illustration with the pump that is being worked on.

Illustration 6	g01238045
Typical port locations and adjustments. (49) P1 Discharge port (50) Pressure port for negative flow control (51) Suction port (52) Case drain port (53) P2 Discharge port (54) Pressure port for negative flow control (55) A3 Discharge port for the pilot pump (56) Gauge port for discharge pressure (57) Gauge port for discharge pressure (58) Suction port for the charge pump

Illustration 7	g01181065
Hydraulic Schematic for type 1 pumps (49) P1 Discharge port (50) Pressure port for negative flow control (51) Suction port (52) Case drain port (53) P2 Discharge port (54) Pressure port for negative flow control (55) A3 Discharge port for the pilot pump (56) Gauge port for discharge pressure (57) Gauge port for discharge pressure (58) Suction port for the charge pump

Illustration 8	g01189417
Hydraulic Schematic for type 1 pumps with negative flow control (49) P1 Discharge port (50) Pressure port for negative flow control (51) Suction port (52) Case drain port (53) P2 Discharge port (54) Pressure port for negative flow control (55) A3 Discharge port for the pilot pump (56) Gauge port for discharge pressure (57) Gauge port for discharge pressure (58) Suction port for the charge pump

Pump Setup

1. Mount the pump with a case drain port (52) upward.

2. Connect pump discharge ports (49) and (53) to the flow meter inlets on the test bench.

3. Connect the discharge port for the pilot pump (55) to an in-line flow meter.

4. Connect the main pump suction port (51) to the test bench oil supply. Connect the suction port for the pilot pump (55) to the test bench oil supply.

5. Verify that the pump case is full of oil before rotating.

6. Do not rotate the pump in the wrong direction. The correct 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)

1. 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 in order to raise the temperature of the oil and purge the system of air.

2. Slowly increase the input RPM to the value in Step 2 of the test specifications. Record the flow value. If the actual flow is less than the value in Step 2 of the test specifications, the pump may not be mechanically feasible. The pump should be internally inspected.

3. Step 3.a through Step 3.c will verify the operation of the torque control.

   1. Increase the discharge pressure on the auxiliary pump according to Step 3.a of the test specifications. Slowly increase the discharge pressure on both discharge ports (49) and (53) according to Step 3.a of the test specifications. Verify the discharge flow.

   2. Slowly increase the discharge pressure on both discharge ports (49) and (53) according to Step 3.b of the test specifications. Verify the discharge flow.

   3. Slowly increase the discharge pressure on both discharge ports (49) and (53) according to Step 3.c of the test specifications. Verify the discharge flow.

4. Step 4.a and Step 4.b will verify the negative flow control. Connect a signal pressure port to one of the pressure ports for negative flow control (50) or (54) .

   1. Slowly apply negative flow control pressure to the pressure port for the negative flow control (50) according to Step 4.a of the test specifications. The pump should begin to destroke at this pressure.

   2. Slowly increase the signal pressure to the pressure port for the negative flow control (50) according to Step 4.b of the test specifications. Verify the discharge flow.

      Note: Repeat steps 4.a and 4.b with signal pressure applied to pressure port for negative flow control (54) .

5. This Step verifies only one pump at a time. Slowly increase the pump discharge pressures according to the values in Step 5 of the test specifications. Measure pump leakage. Calculate the total loss. If the total loss is higher than the allowable value in Step 5 of the test specifications, The pump may not be mechanically feasible.

   Subtract the discharge flow in Step 5 from Step 2. The result is the total loss.

   Example "Step 5 flow"162 L/min (42.8 US gpm) - "Step 2 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).

   Note: Repeat Step 5 in order to verify the opposite pump.

Test Specifications

Test Bench Tooling