Komatsu ecot3 WA430-6 Operation & Maintenance Manual page 225

TROUBLESHOOTING
RELEASING PARKING BRAKE
When releasing the parking brake, stop the machine on level ground and check that the surrounding area is safe. If it is
necessary to release the brake on a slope in an emergency, block the tires before starting the operation.
If the parking brake is released, the brake cannot be used, so check the safety carefully when moving the machine.
If the engine will not run for some reason, use the following methods to release the parking brake and tow the
machine.
METHOD OF RELEASING BRAKE BY USING EMERGENCY PARKING BRAKE CANCEL SWITCH
When the parking brake switch is at the OFF position and the emergency parking brake release valve is opened, the parking brake
is released immediately.
In this condition, even if you feel danger and try to stop the machine, the parking brake will not be applied immediately even if you
close the emergency parking brake release valve.
If the pressure in the brake accumulator is high, do as follows.
1. Turn the starting switch to the OFF position (A).
2. Turn locknut (1) of the release valve counterclockwise, then
turn grip (2) counterclockwise to open the release valve.
REMARK
The relief valve is located on the left front portion inside the rear
frame and secured to the accumulator mounting bracket.
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WARNING
CAUTION
OPERATION