GASKET 6G2885 - Caterpillar

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Tooling (D) 175-5507 Nitrogen Charging Group
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(7) Cap
(8) Nitrogen charging valve
(9) Core
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Tooling (A)
Discharging Procedure
Move the truck to a level area and install wheel chocks. If the use of wheel chocks is not possible, place the wheels in a suitable ditch.Note: Parking on a grade is not acceptable.
Shift the transmission to the park position.
Turn the key switch to the off position.Note: Do not use the battery disconnect switch prior to validating that the accumulators are purged. Turning the battery disconnect switch to the off position will remove power to the Electronic Control Modules. As a result, the accumulator purge process will be aborted.
Wait 3 minutes.
Turn the engine start switch to the on position.Note: Do not start or crank the engine. If the engine is started or cranked, begin the process again.
Operate the steering wheel from side-to-side repeatedly, until the front wheels no longer move.
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View of the service center enclosure for hydraulic gauges
(1) Steering Valve
(2) Steering Accumulator
(3) Hoist Valve
(4) Front Brake
(5) Brake Control Pilot Valve
(6) Brake Supply Accumulator
(7) Front Park Brake
(8) Rear Brake
Use a manual pressure gauge to verify that all pressure has been purged from the accumulators. Check the steering accumulator gauge and brake supply accumulator gauge in the hydraulic cabinet. Check gauges to confirm that pressure is showing zero.
If accumulator pressure is still present, Refer to Operation and Maintenance Manual, "System Pressure Release (Supply Brake Accumulator), (Service Brake Accumulator), and (Steering)" for more information.
After confirming that all accumulator pressure is showing zero, turn off the battery disconnect switch.
Refer to Illustration 3 for the location of the Steering Relief valve. Connect to the valve to release the remaining hydraulic oil into a suitable container.
Identify the correct nitrogen charging chuck.
Attach hose assembly (D11) to nitrogen charging chuck (D9) or (D10).
Turn valve handle of nitrogen charging chuck (D9) or (D10) all the way in the counterclockwise direction.Note: Turning the valve handle will ensure that nitrogen charging valve (8) will not be opened when nitrogen charging chuck (D9) or (D10) is attached.
Remove cap (7) from the nitrogen charging valve (8).
Attach nitrogen charging chuck (D9) or (D10) to nitrogen charging valve (8).Note: During this step, observe the pressure reading for each accumulator before releasing the nitrogen. The pressure of a properly charged accumulator should be 10342 690 kPa (1500 100 psi). If the nitrogen pressure of the accumulator is significantly below the expected pressure, a rebuild of the accumulator is required. Reference the following procedures for removal, disassembly, and assembly of faulty accumulators:For removal of the steering accumulator, refer to Disassembly and Assembly, UENR2271, "Accumulator (Steering) - Remove and Install".For disassembly of the steering accumulator, refer to Disassembly and Assembly, UENR2271, "Accumulator (Steering) - Disassemble".For assembly of the steering accumulator, refer to Disassembly and Assembly, UENR2271, "Accumulator (Steering) - Assemble".
Turn valve handle of nitrogen charging chuck (D9) or (D10) in the clockwise direction to open nitrogen charging valve (8). Turning the valve handle will release all the nitrogen from the accumulator through hose assembly (D11).Testing and Charging