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Diesel engine exhaust contains products of combustion which may cause personal injury. Always start and operate the engine in a well ventilated area, and, if in an enclosed area, vent the exhaust to the outside. |
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Personal injury can result from rotating and moving parts. Stay clear of all rotating and moving parts. Never attempt adjustments while the machine is moving or the engine is running unless otherwise specified. The machine must be parked on a level surface and the engine stopped. Attach a "Do Not Operate" or similar warning tag to the start switch and controls before servicing, repairing, or making adjustments to the machine. |
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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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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, and the 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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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. |
| Required Tools | |||
|---|---|---|---|
| Tool | Part
Number |
Description | Qty |
| A | 8T-0860 | Pressure Gauges
|
1 |
| 6V-4144 | Quick Connect Couplers | 1 | |
| B | 177-7860 | Hose As | 1 |
| 6V-4142 | Fittings | 2 | |
| 6V-4143 | Quick Connect Couplers | 2 | |
| Optional Tools(1) | |||
|---|---|---|---|
| Tool | Part Number | Description | Qty |
| C(2) | 198-4234 | Pressure Gauge Tool Gp | 1 |
| D(2) | 198-4236 | Adapter Cable As | 2 |
| E(2) | 198-4238 | Pressure Sensor Gp
|
2 |
| (1) | The optional tools can be used to replace the analog pressure gauges in the required tool list. |
| (2) | Tool (C), Tool (D), and one Tool (E) are part of the 198-4240 Digital Pressure Indicator. |
Note: The illustrations in the following procedure show the Water Delivery System installed on a 777F Off-Highway Truck.
- Drive the machine to a smooth, horizontal surface.
- Place the transmission gear selector in the PARK position.
- Apply the brakes. Place blocks in front of the rear wheels and behind the rear wheels. Do not place blocks around the front wheels.
- Operate the engine at high idle.
- Turn the steering wheel to the right until the steering cylinder stop is reached. Continue turning the steering wheel against the stop. Hold the steering wheel in this position for 3 seconds and then release the steering wheel. Continue this step until the oil in the steering system reaches a temperature between
38 °C (100 °F) and93 °C (200 °F) . - Operate the engine at low idle for a few minutes. Shut down the engine.
- Assemble Tool (A) and Tool (B). Connect Tool (A) to Tool (B).
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Illustration 1 g02763736 - Locate steering check and relief valve (2) on the machine frame behind the right front suspension cylinder.
- Install Tool (B) on pressure tap (1) for the steering system.
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Illustration 2 g02763879 - Locate high-pressure cutoff valve (5) on the steering pump.
Note: It may be necessary to lift the water tank for the machine in order to access these components. If the machine is equipped with a hoist system, consult the applicable Operation Manual. If the machine is not equipped with a hoist system, reference the technical literature of the tank manufacturer for recommendations on lifting the thank.
- Loosen locknut (4) of high-pressure cutoff valve (5).
- Rotate adjustment screw (3) clockwise 1.5 turns. This action will increase the pressure setting of the high-pressure cutoff valve above the pressure setting of the backup relief valve for the primary steering.
Note: Do not increase the pressure setting of the relief valve too much. If the pressure setting of the relief valve is set too high, damage to the components of the system could occur.
- Tighten locknut (4).
- Start the engine. Operate the engine at low idle.
- Place the transmission gear selector in the NEUTRAL position.
Note: When the transmission gear selector is in the PARK position, friction from the wheel brakes will not allow the secondary steering system to turn the wheels all the way to the cylinder stops.
- Rotate the steering wheel until the steering cylinder stop is reached. Continue turning the steering wheel against the stop.
- Check pressure on Tool (A). The pressure setting of backup relief valve for the primary steering is
26000 ± 400 kPa (3771 ± 58 psi) . - Release the steering wheel.
- Place the transmission gear selector in the PARK position in order to apply the parking brakes.
- Shut down the engine.
- If the pressure is within the specified range, go to Step 26. If the pressure is not within the specified range, go to Step 19.
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Illustration 3 g02763886 - Loosen locknut (8) of backup relief valve (6) for the primary steering.
- Use an Allen wrench to rotate adjustment screw (7) in order to adjust the pressure setting. Rotate adjustment screw clockwise in order to increase the pressure setting. Rotate adjustment screw counterclockwise in order to decrease the pressure setting.
Note: Each one quarter turn of the adjustment screw changes the pressure approximately
1183 kPa (172 psi) . - Tighten locknut (8).
- Go to Step 14 and retest.
- Loosen locknut (4) of high-pressure cutoff valve (5).
- Rotate adjustment screw (3) counterclockwise 1.5 turns in order to reset the pressure setting for the high-pressure cutoff valve.
- Tighten locknut (4).
- When the pressure setting of the backup relief valve for the primary steering is correct, adjust the pressure setting of the high-pressure cutoff valve to the original pressure setting. Refer to Testing and Adjusting, "Piston Pump (Steering) Pressure - Test and Adjust" for the correct procedure.
