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Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system. |
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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. |
| Required Tools | |||
|---|---|---|---|
| Tool | Part Number | Description | Qty |
| A | 198-4234 | Digital Pressure Indicator | 1 |
| 198-4239 | Pressure Gauge 0 - 69000 kPa (0 - 10000 psi) |
1 | |
| 198-4238 | Pressure Gauge 0 - 3450 kPa (0 - 500 psi) |
1 | |
| B | 4C-6500 | Digital Thermometer | 1 |
Note: Perform the Relief Valve (Charge)–Test and Adjust procedure before you perform this procedure.
Note: Perform the following steps before conducting this procedure:
- Park the machine on a flat, level surface.
- Block the wheels.
- Engage the parking brake.
- Stop the engine.
- Loosen the set screw. Rotate needle valve (1) clockwise until the valve seats. Tighten the set screw.
Note: Needle valve (1) is located in the engine compartment on the right side of the machine.
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| Illustration 1 | g01087212 |
(1) Needle valve | |
- Connect one 0 - 3450 kPa (0 - 500 psi) pressure sensor from Tool A to charge pressure tap (2). Connect the 0 - 69,000 kPa (0 - 10,000 psi) pressure sensor from Tool A to forward pressure tap (3) on the propel pump.
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| Illustration 2 | g01087192 |
(2) Charge pressure tap (3) Forward pressure tap | |
- Start the engine. Operate the engine at 2250 rpm (high idle). Monitor the hydraulic oil temperature with Tool B. Operate the machine until the oil temperature reaches 43° ± 5.6°C (110° ± 10°F).
- Move parking brake switch (5) to OFF. Move shift switch (6) to HIGH.
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| Illustration 3 | g01086971 |
- With the machine at high idle, move propel lever (4) forward until the pressure at forward pressure tap (3) reaches 10340 kPa (1500 psi).
- Read the pressure at charge pressure tap (2) on Tool A. Record this pressure as "flushing relief pressure".
- Move propel lever (4) back to NEUTRAL. Read the charge pressure on Tool A. Record this pressure as "charge pressure".
- The pressure differential between flushing relief pressure and charge pressure should be 120 ± 70 kPa (17 ± 10 psi).
- Move parking brake switch (5) to ON. Stop the engine. Remove the tooling. Loosen the set screw. Rotate needle valve (1) counterclockwise until the valve stops. Tighten the set screw.