- Wheel Loader
- 988K (S/N: T8E1-UP; L8X1-UP; LWX1-UP; TWX1-UP)
- 988K XE (S/N: E8X1-UP; EWX1-UP)
- Wheel Tractor-Scraper
- 631K (S/N: WTR1-UP; WTW1-UP)
- 637K (S/N: WTS1-UP; WTT1-UP; WTX1-UP; WTY1-UP)
Introduction
Revision | Summary of Changes in REHS3636 |
03 | Updated effectivity. |
02 | Updated effectivity. |
01 | Added new part number 398-1956 Piston Pump Gp. to document. |
Added new Wheel Tractor Scraper serial number prefix WTS to document. | |
Added new Wheel Tractor serial number prefixes WTX, WTW, and WTR to document. | |
Added new Wheel Scraper serial number prefixes WTY and WTT to document. | |
00 | New Document. |
© 2018 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, please 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
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. |
Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin. |
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) in order to view the latest version.
References
References | |
---|---|
Media Number | Title |
REHS1761 | "Required Tooling for Bench Testing Hydraulic Components" |
SEBF8810 | "Hydraulic Pump, Motor, and Cylinder Bench Test Procedure Reference Manual" |
SEHS8892 | "Operating Instructions for Caterpillar 1U-9400 Series Hydraulic Test Center" |
NEHS0563 | "Tool Operating Manual for 9U-5000 Series Hydraulic Test Bench" |
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) Outlet for the auxiliary oil supply (34) Inlet for the auxiliary oil supply (35) "Flow meter 1" inlet |
Illustration 5 | g01063316 |
Control and Gauges for the test bench (36) Supply pressure for the auxiliary oil (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) Control for the auxiliary oil supply (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 | g03386254 |
Port locations (49) Adjustment screw for high-pressure cutout (50) Adjustment screw for margin pressure (51) pressure port for load sensing (52) Discharge port (53a) Case drain (53b) Case drain (53c) Case drain (53d) Case drain (54) Gage port for control pressure (55) Adjustment screw for maximum displacement (56) Adjustment screw for minimum displacement (57) Suction port |
Illustration 7 | g03386255 |
Hydraulic schematic (49) Adjustment screw for high-pressure cutout (50) Adjustment screw for margin pressure (51) Pressure port for load sensing (52) Discharge port (53a) Case drain (53b) Case drain (53c) Case drain (53d) Case drain (54) Gage port for control pressure (55) Adjustment screw for maximum displacement (56) Adjustment screw for minimum displacement (57) Suction port |
Illustration 8 | g03386726 |
|
Illustration 9 | g03386728 |
|
Illustration 10 | g03386729 |
Schematic for (58) Outlet port (59) Adjustment for the discharge flow (60) Inlet port (61) High-pressure port (62) Adjustment for the discharge pressure (63) Low-pressure port (64) Pressure port for the load sensing |
Illustration 11 | g03386730 |
(58) Line to the flow meter on the test bench (59) Adjustment knob for discharge flow (60) Line from the pump discharge port (61) To the high side of the differential gauge (62) Load control for pump discharge pressure (63) Line to the low side of the differential gauge (64) Pressure port for load sensing (65) Pressure differential gauge group (66) Line to the low side of the load sensing group (67) Line to the high side of the load sensing group |
Pump Setup
Note: A sense pressure line from the pump should be connected to the load sensing pressure port (7) when you use the Caterpillar Hydraulic Test Center. A sense pressure line from the pump should be connected to the pressure port for load sensing (64) on the 4C-3582 Load Sensing Valve when using the Caterpillar Hydraulic Test Bench.
- Connect a one inch high pressure "XT6" hose from the pump discharge port (52) to inlet port (60) on the 4C-3582 Load Sensing Valve.
- Connect a one inch high pressure "XT6" hose from outlet port (58) on the 4C-3582 Load Sensing Valve to the flow meter inlet on the test bench.
- Connect a one inch high-pressure hose from the outlet of the flow meter on the test bench back to the tank.
- Connect a 6D-7726 Hose Assembly to the pressure port for load sensing (64). Connect the other end of 6D-7726 Hose Assembly to the pressure port for load sensing (51) 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.
- Connect the 1U-5796 Pressure Differential Gauge Group (65) to the high-pressure valve port (61) and low-pressure valve port (63) on the 4C-3582 Load Sensing Valve. The port marked "hi" (67) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "hi" (61) on the 4C-3582 Load Sensing Valve. The port marked "low" (66) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "low" (63) on the 4C-3582 Load Sensing Valve.
Note: The ports marked "low" (63) and "sense line" (64) on the 4C-3582 Load Sensing Valve are reading the same pressure.
- Purge all air from the suction line. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction hose.
- Fill the pump case with oil. Pour oil directly into a case drain port until the case is full.
- Connect an in-line flow meter to the case drain port (53a), (53b), (53c), or (53d). Direct the oil from the in-line flow meter back to the tank.
- 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 in the test specification tables 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)
- 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.
- Slowly increase the input RPM to the value in Step 2 of the test specifications. If the actual flow is less than the value given in Step 2 of the test specifications, the pump may not be mechanically feasible. The pump should be internally inspected.
- Slowly increase the input RPM to the value in Step 3. The discharge flow is adjusted by using the 4C-3582 Load Sensing Valve. Bench circuitry will be used for flow limiting when you use a 1U-9400 Test Center.
Decrease the discharge flow by turning adjustment for discharge flow (59) according to the values in Step 3 of the test specifications. Adjust the discharge pressure according to the values in Step 3 of the test specifications. Adjust the screw for margin pressure (50) to the value in Step 3 of the test specifications. The margin pressure will be displayed on the 1U-5796 Pressure Differential Gauge (65).
Note: The margin pressure may change as discharge pressure changes. Adjust margin pressure in Step 3 only.
- Increase the discharge flow by turning adjustment for discharge flow (59) according to Step 4 of the test specifications. Slowly decrease the input RPM to the value in Step 4. Increase the pump discharge pressure to the value in Step 4 of the test specifications. Compare the actual values from the case drain with the values in Step 4 of the test specifications. This value is an indication of the pump efficiency. If the case drain is more than the value given in Step 4 of the test specifications, the pump may not be mechanically feasible. The pump should be internally inspected.
- Increase the pump discharge pressure to the value in Step 5 of the test specifications. If the high pressure cut out value is not equal to the value in Step 5 of the test specifications, then turn the adjustment screw for the high-pressure cutout (49) until the actual high pressure cut out value is equal to the value in Step 5. The discharge flow should be zero when the high-pressure cutout is reached.
Illustration 12 | g01181482 |
Pump characteristics (P) Discharge pressure (Q) Discharge flow |
Note: For Steps 1,2,4, and 5 be sure Adjustment knob for discharge flow (59) and Adjustment for the discharge pressure (62) are backedcompletely out on the 4C-3582 Load Sensing Valve.
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
Part Number | Pump Rotation | Step | Input Speed | Discharge Pressure kPa (psi) | Discharge Flow lpm (gpm) | Max. Case Drain Flow lpm (gpm) | Margin Pressure kPa (psi) |
347-5023 | Double pump composed of 362-9620 (this document) and 384-9438 (see REHS1793). |
Part Number | Pump Rotation | Step | Input Speed | Discharge Pressure kPa (psi) | Discharge Flow lpm (gpm) | Max. Case Drain Flow lpm (gpm) | Margin Pressure kPa (psi) |
362-9620 | CW | 1 | 1000 | 0 | 145 (38) | - | - |
2 | 2200 | 0 | 319 (84) | - | - | ||
3 | 2200 | 25000 (3630) | 159 (42) | - | 2100 (305) | ||
4 | 1000 | 28800 (4180) | 145 (84) | 10 (2.6) | - | ||
5 | 1000 | 32000 (4640) | 0 | - | - |
Part Number | Pump Rotation | Step | Input Speed | Discharge Pressure kPa (psi) | Discharge Flow lpm (gpm) | Max. Case Drain Flow lpm (gpm) | Margin Pressure kPa (psi) |
398-1956 | CCW | 1 | 1000 | 0 | 145 (38) | - | - |
2 | 2200 | 0 | 319 (84) | - | - | ||
3 | 2200 | 25000 (3650) | 159 (42) | - | 2100 (300) | ||
4 | 1000 | 23400 (3400) | 145 (84) | 10 (2.6) | - | ||
5 | 1000 | 26000 (3800) | 0 | - | - |
Tooling
Tooling | |||||||
Part Number | Adapter Plate | Drive Adapter | Suction Adapter | Split Flange | Flange Adapter | Pilot Pressure Port | Case Drain Port |
347-5023 | Double pump composed of 362-9620 (this document) and 384-9438 (see REHS1793). | ||||||
362-9620 | 1U-9129 | 1U-9835 | 1U-9866 | 1P-5767 | 9U-7440 | 9/16-18 STOR | 1 1/16-12 STOR |
398-1956 | 1U-9129 | 1U-9835 | 1U-9866 | 1P-5767 | 9U-7440 | 9/16-18 STOR | 1 1/16-12 STOR |