YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
5-11
YES
Is MCV pilot
pressure same
for LH and RH?
Clogged or oil
leak.
Check if pilot
piping is not
clogged or does
not have oil
leakage.
Does swing control
valve spool move
smoothly by hand?
Does symptom
change when LH
and RH port relief
valves are
exchanged
SWING MOTION IS IMPOSSIBLE IN ONE DIRECTION
3)
Is swing control
valve's return
spring normal?
Is gear pump pilot
pressure within
standard level?
Does swing control
valve spool move
smoothly by hand?
Is MCV pilot
pressure within
standard value?
MACHINE SWINGS BUT DOES NOT STOP
4)
Pilot relief valve is
faulty.
Gear pump is
broken.
Pilot valve is faulty.
Swing control
valve spool is
stuck.
Return spring is
faulty.
Disassemble and
repair or replace.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
replace.
Swing port relief
valve is faulty.
Shuttle valve is
faulty.
Swing control valve
spool is stuck.
Pilot valve is faulty.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Clean pilot piping
interior or repair
piping.
Cause
Remedy
Cause
Remedy