Final drive Fault diagnosis for PC400-7 komatsu excavator

Malfunction: unable to walk on one side
Check reason: dirty stuff blocked the small hole (k) on the balance valve, resulting in parking system Momentum cannot be undone.
Fault analysis : The dirt enters and blocks the small hole k in the balance valve.Walk,
The pressure oil can not pass through the small hole k on the balance valve and enter the balance, The spring chamber of the valve pushes the balance valve to move, therefore, to gram
The pressure oil of the brake spring cannot pass through the balance valve Slot entry, resulting in failure to remove stop braking force, results row , A walking motor can’t rotate, so it can’t walk.
Fault disposal: clean the balance valve, and pay attention to the future disassembly to avoid dirty east into the west.