| Required Tools | ||
| 4C4892 | ORFS Fittings Group | 1 |
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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train. |
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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of all fluids according to local regulations and mandates. |
- Use the following procedure before you perform testing and adjusting:
- Apply the parking brake.
- Place the propel control lever in NEUTRAL.
- Place wedges of wood under each drum.
- Apply the parking brake.
- Remove plugs (1). Connect a jumper hose between ports (X1) and (X2). This will equalize the oil pressure on each side of the servo piston.
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| Illustration 1 | g00692481 |
Servo On The Propel Pump (1) Two plugs (X1) and (X2). | |
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| Illustration 2 | g00692504 |
(2) Pressure tap (3) Pressure tap (4) Locknut | |
- Connect two 60000 kPa (8702 psi) gauges from the 4C-4892 ORFS Fittings Group to pressure taps (2) and (3) .
- Move the selector switch to the LOW SPEED range.
- Start the engine. Run the engine at 1500 rpm.
- Look at the pressure gauges. Both gauges should have the same reading.
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| Illustration 3 | g00692509 |
Hydraulic servo (4) Locknut | |
- If it is necessary to adjust the neutral position of the piston, loosen locknut (4). Use an allen wrench to turn the adjustment screw on the piston rod. Turn the screw in the clockwise direction or the counterclockwise direction. The pressures on the gauges should change. Adjust the screw until the pressures have the same reading.
- Stop the engine. Remove the 60000 kPa (8702 psi) gauges. Connect two 4000 kPa (580 psi) gauges.
- Repeat Steps 5 through 8.
- Tighten locknut (4). Remove the pressure gauges, hoses, and connectors from the pressure taps (2) and (3). Remove the jumper hoses from ports (X1) and (X2). Install plugs (1) .