Komatsu WA500-6H Operation & Maintenance Manual page 243

Operation
Method of releasing brake by using emergency parking
brake cancel switch
CAUTION
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 starting switch to the ON position (B).
2. Set the emergency parking brake switch to the "RELEASE"
position.
When doing this, check that the warning lamp for the parking
b r a k e g o e s o u t . W h e n t h e s w i t c h i s t u r n e d t o t h e
"RELEASE" position, the alarm buzzer sounds continuously.
REMARK
Normally, keep this switch at the "NORMAL" position.
If the brake accumulator pressure is low, the parking brake
warning lamp may not go out and the alarm buzzer may make a
continuous high-pitched sound.
If this happens, release the brake. For details, see "Method of
releasing mechanically (3-178)".
WA500-6H – VEAM430100
3.7 Troubleshooting
A
B
C
GK050049
GK050178
3-177