Komatsu PC88MR-10 Shop Manual page 266

10 Structure and function
Electrical control system
Function
When L.H. work equipment control lever is set to NEUTRAL, the swing parking brake
works in approximately 5 sec.
Operation Swing parking brake is released and the swing operation can be performed freely when L.
H. work equipment control lever is operated to swing or to arm IN, or the boom swing
pedal is operated.
A: L.H. work equipment control lever in "SWING" (Swing parking brake "RELEASED")
B: L.H. work equipment control lever in "NEUTRAL"
C: Swing parking brake "operates"
D: 5 seconds
Swing parking brake cancel function
If the swing parking brake does not operate normally and the upper structure cannot swing because of
trouble in the controller, etc., the operator can swing by releasing the swing parking brake with swing
parking brake cancel switch (2).
a: Release (when abnormal)
b: Normal (when normal)
Swing parking
brake
cancel switch
Swing brake Swing parking brake is released (*1)
*1: Operation of hydraulic brake by safety valve
a While the swing parking brake is released, only the hydraulic brake by the safety valve is applied. If swing
is stopped on a slope, the hydraulic drift may occur. Take care.
a Swing parking brake cancel switch (2) is alternate type. When it is set to the "RELEASE (a)" position, the
swing lock pilot lamp on the machine monitor flashes.
10-188
Cancel
(When controller is abnormal)
Swing parking brake
Normal (When controller is normal)
Swing parking brake operates
PC88MR-10