Bench Test Procedure for Hydraulic Piston Pumps{3203, 5070} Caterpillar

Paving Compactor:

CP-323C (S/N: 6DM202-UP; EAS1-UP)

CS-323C (S/N: 1EN167-UP; DAR1-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

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• Cat Technical Representative

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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.

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.

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.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 1	g01096597
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	g01096600
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	g01096604
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 4	g01096607
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 pump oil supply outlet (34) Auxiliary pump oil supply inlet (35) "Flow meter 1" inlet

Illustration 5	g01096608
Control and Gauges for the Test Bench (36) Auxiliary pump pressure (37) Signal pressure (38) Control for signal pressure (39) "Flow meter 1" discharge pressure (40) Control for auxiliary pump pressure (41) "Flow meter 2" discharge pressure (42) Auxiliary pump flow 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	g01129687
Typical port locations and adjustments. (49) Manual displacement lever (50) Case drain port (51) Discharge port (52) Charge pump suction port (53) Adjustment screw for charge relief valve (54) Port for input charge flow (55) Charge pump discharge port (56) Multi-function valve (57) Multi-function valve

9U-5902 Rectifier Block

Illustration 7	g01096617
9U-5902 Rectifier Block Connections

Illustration 8	g01096619
9U-5902 Rectifier Block Schematic (58) High-pressure port "from pump discharge" (59) Outlet "to flow meter loop" (60) High-pressure port" from pump discharge" (61) Low-pressure return "from heat exchanger"

9U-5893 Heat Exchanger

Illustration 9	g01096620
9U-5893 Heat Exchanger Connections (62) Inlet "from flow meter loop" (63) Outlet "to rectifier block" (64) Water inlet (65) Water outlet

Pump Pre-Test Setup

1. Mount the pump with a case drain port (50) upward.

2. Connect pump discharge ports (51) to the 9U-5902 Rectifier Block high-pressure ports (58) and (60).

3. Connect the 9U-5902 Rectifier Block outlet (59) to the flow meter inlet of the test bench.

4. Connect the "flow meter outlet" to the 9U-5398 Heat Exchanger inlet (62) .

5. Connect the 9U-5398 Heat Exchanger outlet (63) to the low-pressure return (61) on the 9U-5902 Rectifier Block .

6. Connect the charge pump suction port (52) to the test bench oil supply.

7. Connect an in-line flow meter to the case drain port (50) .

8. 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 hose.

9. Fill the pump case with oil before rotating. Pour oil directly into a case drain port (50) until the case is full.

Test Procedure

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

The hydraulic oil in the test bench should meet an ISO rating of 16/13. 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 Step 1 of the test specifications. Listen for abnormal noise. Verify flow from the charge pump. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around the control valves. Compare the charge pressure with the value in Step 1 of the test specifications. If the charge pressure is not within the test specifications, adjust accordingly. Turn the adjustment screw for charge relief valve (53) clockwise in order to increase the pressure. Turn the adjustment screw for the charge relief valve (53) counterclockwise in order to decrease the pressure.

2. Slowly shift the mechanical displacement lever (49) in one direction and increase the input RPM according to Step 2 of the test specifications. 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. Slowly increase the discharge pressure to the value in Step 3 of the test specifications. Measure pump efficiency. Calculate the total loss. If the total loss is higher than the allowable value in Step 3 of the test specifications, the pump may not be mechanically feasible.

   Find the total loss. Subtract the discharge flow in Step 3 from the discharge flow in Step 2. This is the total loss.

   Example: "Step 3 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).

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

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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 according to Step 4 of the test specifications. The pump should be fully destroked when the discharge pressure in Step 4 is reached.

   Decrease the discharge pressure and input RPM. Shift the mechanical displacement lever (49) in the opposite direction and repeat Steps 2 and 4 of the test specifications.

Test Specifications

Test Bench Tooling