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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. |
| 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. |
| Pilot Accumulator Pressure | ||
| Item | Setting | Actual |
| Pilot system pressure at low idle | |
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This information includes the following test:
- Pilot Oil Accumulator (Dead Engine Lift arm lower) - Test and Charge
- Dead Engine Lift Arm Lower (No Engine) Manual Lower
| |
| Illustration 1 | g03677521 |
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Tooling (A) 198-4240 Digital Pressure Indicator Gp | |
| Required Tools | ||||
|---|---|---|---|---|
| Tool | Item | Qty | Part No | Description |
| A | 198-4240 | Digital Pressure Indicator Gp | ||
| A1 | 1 | 198-4234 | Digital Indicator | |
| A2 | 1 | 198-4237 | Pressure Sensor Gp
(0 to 3,445 kPa (0 to 500 psi)) |
|
| A2 | 1 | 198-4238(1) | Pressure Sensor Gp
(0 to 34,450 kPa (0 to 5,000 psi)) |
|
| A2 | 1 | 198-4239 | Pressure Sensor Gp
(0 to 41,368 kPa (0 to 6,000 psi)) |
|
| A2 | 1 | 251-9600(2) | Pressure Sensor Gp
(0 to 68,900 kPa (0 to 10,000 psi)) |
|
| A3 | 1 | 198-4236 | Adapter Cable As | |
| (1) | This sensor must be purchased separately, this sensor is not included in the 198-4240 Digital Pressure Indicator Gp |
| (2) | This sensor can only be used on large diameter pressure taps like 6V-3965 Fitting. |
Refer to Testing and Adjusting, "Machine Preparation for Testing and Adjusting".
Refer to Testing and Adjusting, "System Pressure Release".
Pilot Oil Accumulator (Dead Engine Lift arm lower) - Test and Charge
The pilot oil accumulator will hold pressure for upwards of 3 minutes. In the event the blade lift arms are up and the engine is dead but the machine still has electrical power the blade can still be lowered.
- Lower the lift arms and blade to the ground.
- Turn the engine key to OFF position.
- Relieve pressure from the pilot hydraulic system.
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Illustration 2 g03677531 - Attach tooling "A" to the pilot pressure tap located on the pilot manifold inside the front frame. Use a gage rated for
3445 kPa (500 psi) . - Move steering lock to LOCKED position.
- Start the engine.
- Bring the hydraulic oil up to temperature.
- Run the engine at high idle for 2 minutes to be sure that the pilot accumulator has been charged.
- Move the lift arms and blade to the Raised position.
- Turn off the engine. and record the pilot pressure
- The pilot accumulator pressure should be
3700 ± 500 kPa (537 ± 73 psi) . - Turn the starting switch to the ON position but do not start the machine.
- Move the implement joystick to the fully Lowered position.
- Lift cylinders should allow blade to lower to the ground as the lower spool in the implement valve shifts and is allowed to vent pressure back to the tank.
- Relieve any pressure in the hydraulic system.
- Remove tooling "A".
- Place steering lock back to the STORED position.
- Turn starting switch to OFF.
Dead Engine Lift Arm Lower (No Engine) Manual Lower
- Move the steering frame lock to the LOCKED position.
- Start the engine and warm up the hydraulic system oil to temperature.
- Move the lift cylinders and blade to fully Raised.
- Turn off the engine.
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Illustration 3 g03677788 - Locate the manual lower valve at the articulation joint on the right side of the machine.
- Turn the manual lowering valve to allow oil from the rod end of the lift cylinders to return to tank.
- Lift cylinders will extend and allow the blade to lower to the ground.
- Move steering lock to STORED position.
