- Paving Compactor:
- CB-334D (S/N: DCZ1-UP; 4CZ1-UP)
- CB-335D (S/N: D4E1-UP; 5PZ1-UP)
| Required Tools | ||
| Part Number | Description | Quantity |
| 8T-0861 | Pressure Gauge 60000 kPa (8700 psi) |
1 |
| 8T-0855 | Pressure Gauge 4000 kPa (600 psi) |
1 |
| 6V-8730 | Union | 1 |
 |
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 |
|---|
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
- Make sure that the parking brake is applied.
- Make sure that the propel control lever is in NEUTRAL position.
- Make sure that the manual displacement control is in the NEUTRAL position.
- Place blocks under both sides of the drums and the tires (if equipped).
- Set the brakes by disconnecting the wiring harness for brake solenoid (1). The wiring harness is identified by wire number 777-PU.
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| Illustration 1 | g01043899 |
Brake Interlock Valve (1) Wiring harness for the brake solenoid | |
- Disconnect the lines for interlock line (2) and (3). Cap the fittings for the interlock line immediately. Connect the ends of interlock lines (2) and (3) together with a union. This will equalize the oil pressure on each side of the servo piston.
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| Illustration 2 | g01043901 |
Brake Interlock valve (2) Interlock Line (INT2) (3) Interlock Line (INT1) | |
- Connect two 60000 kPa (8702 psi) pressure gauges into the ends of the test ports (4) and (5) .
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| Illustration 3 | g01043902 |
Propel Pump (4) Forward Relief Valve Test Port (5) Reverse Relief Valve Test Port | |
Note: The pump is removed for photographic purposes.
- Put the propel control lever in the LOW SPEED range. Start the engine. Run the engine at 1500 rpm.
- Look at the pressure gauges. The difference in the pressure reading is the offset pressure.
- If the offset pressure is not zero, it is necessary to adjust the neutral position of the piston. In order to adjust the neutral position of the piston, loosen locknut (7) of the servo valve neutral adjustment screw (6) .
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| Illustration 4 | g01043903 |
(6) Neutral Adjustment Screw (7) Locknut | |
Note: Replace the gauges with two 4000 kPa (580 psi) gauges in order to achieve finer resolution.
- Turn the neutral adjustment screw (6) clockwise until the pressure gauge shows an increase in pressure. Mark the position of the screw.
- Turn the neutral adjustment screw (6) counterclockwise until the other pressure gauge shows an increase in pressure. Mark the position of the screw.
- Turn the screw clockwise to a position that is halfway between the positions that are marked.
- Look at the pressure gauges. The pressures on the two gauges should be equal.
- Once the neutral has been found, hold the adjustment screw (6). Tighten locknut (7) to a torque between 28 N·m (21 lb ft) and 51 N·m (38 lb ft).
- Stop the engine. Remove the pressure gauges. Remove the union from interlock line (2) and (3). Reconnect interlock lines (2) and (3) to the brake interlock valve. Reconnect the wiring harness (1) for the brake solenoid.
- Remove the blocks from the drums and the tires (if equipped).