Variable Frequency
| Required Tools | ||
| Part Number | Description | Qty |
| 8T-0855 (1) | Pressure Gauge | 2 |
| ( 1 ) | Part of 4C-4892 Fittings Group |
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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
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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. |
Note: Perform the Pump Servo Neutral - Adjust before doing this test. The position of the servo piston will affect the pressure readings that are obtained from the adjustment of the eccentric screw.
- Make sure that the parking brake is applied. Make sure that the propel control lever is in neutral.
- Remove the plugs from servo ports (1) .
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| Illustration 1 | g00462271 |
Vibratory Pump (1) Servo ports. (2) Adjustment screw. (3) Pump control. | |
- Assemble the two 8T-0855 Pressure Gauges with the proper fittings from 4C-4892 Fittings Group. Install the two pressure gauges at servo ports (1) .
- Start the engine and run the engine at 1200 rpm.
- Read the pressure on the two pressure gauges. If the pressures are not identical, the pump control must be adjusted.
- To adjust the pump control, loosen the locknut and turn adjustment screw (2) in either direction in order to attain equal pressures on the two pressure gauges. When the pressures are equal, hold the adjustment screw and tighten the locknut.
Note: Adjustment screw (2) is an eccentric adjuster. One half of a revolution of the adjustment screw gives all the adjustment that is possible. A small amount of movement of the adjustment screw (2) makes a large pressure change.
- Stop the engine. Remove the two pressure gauges from servo ports (1), and install the two plugs.