VALVE-BREAKER RELIEF 1179152 - Caterpillar

Shock/Electrocution Hazard! Do not work on this equipment unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in serious injury or death.
Introduction
The rotor brake provides a safety mechanism during rotor maintenance. The procedure provides a method to check the condition of the rotor brake and if necessary, adjustment procedures.Test Preparation
Park the machine on a smooth, horizontal surface.
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Move propel lever (1) to the NEUTRAL position.
Move parking brake switch (2) to the ON position.
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Press rotor raise switch (3). Release the rotor raise switch when the rotor is fully raised.
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Press chamber tilt switch (4). An indicator light next to the chamber tilt switch will illuminate when the chamber is in TILT DOWN position.
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Press rear door switch (5) to raise the rear door fully.
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Press throttle control switch (6) in order to place the engine in low idle. Note: Two things indicate when the engine is at low idle. First, the engine rpm will appear on machine display (7). Second, the indicator light next to the throttle switch will go out.
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Move engine start switch (8) to the OFF position in order to shut off the engine.
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Install rotor lock mechanism (9). Secure with pin (10).
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Install lock (11) on the rear door (12). Test Procedure
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Open electrical panel (13) near the left ladder.
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Move rotor service switch (14) to the SERVICE position. The electric motor should cycle on and then stop. If the electric motor does cycle on, and then stop, go to Step 4. If the electric motor does not cycle on and then stop, go to "Adjustment Procedure".
Attempt to rotate the rotor by hand. If the rotor rotates, the brake release system is operating properly. If the rotor does not rotate, go to "Adjustment Procedure", Step 4.
Move rotor service switch (14) to the RUN position. Close electrical panel (13).
Disengage lock (11) on the rear door (12).
Remove pin (10). Disengage rotor lock mechanism (9). Secure the pin. Adjustment Procedure
If the electric motor continues to cycle on and off every 10 seconds, refer to the procedure in Specifications, Systems Operation, Testing, and Adjusting, KENR3134, "Hydraulic Accumulator (Parking Brake) - Test and Charge".
If the electric motor does not cycle on, and then off, troubleshoot the motor circuit.
If the pump continues to run, troubleshoot the pressure switch and/or the relief valve on the brake valve.
If the rotor does not rotate, troubleshoot the electrical circuit for the rotor service switch.
Go to "Test Procedure", Step 2 in order to recheck the rotor brake.