Hydraulic System For Working Device - Hyundai HL630VL Operator's Manual

HYDRAULIC SYSTEM FOR WORKING DEVICE

Characteristics of faults
Arm lifting force or bucket
digging up force inadequate
Bucket or arm rises slowly
even at high speed of engine
Cause
Wear or damage of cylinder oil seal
Distribution valve excessively worn.
Fit clearance between valve stem
and valve body exceeds the specified
value
Oil leakage in pipeline system
Severe internal leaking of working
pump
Improper adjustment of safety valve,
and system pressure too low
Oil suction pipe and oil filter blocked
See above
Dual action safety valve blocked
Remedy
Replace oil seal
Disassemble, check and repair
to make the clearance meet
requirements on specified value , or
replace distribution valve
Locate the leakage point and repair
Replace working pump
Adjust the system pressure to the
specified value
Clean oil filter and change oil
See above
Disassemble the dual action safety
valve to check
Troubles Shooting 6-3