YES
5-9
4. SWING SYSTEM
BOTH LH AND RH SWING ACTIONS ARE IMPOSSIBLE
1)
Are attachment
and travel
motions
impossible at all?
Is safety solenoid
valve pressure
within standard?
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
Is gear pump pilot
pressure within
standard level?
Is MCV pilot
pressure within
standard level?
Is swing brake
release valve
faulty?
Are broken pieces
of coupling present
when dust plug
under engine fly
wheel is removed?
Is oil in hydraulic
tank within
standard level?
Does dozer
function?
Cause
Remedy
Safety valve faulty
or not operated.
Gear pump faulty.
Pump connection
coupling is broken.
Hydraulic pump is
out of order.
Swing control valve
spool is stuck.
Hydraulic pump is
broken.
Swing brake
release valve is
broken.
Swing reduction
unit is broken.
Swing motor is
broken.
Pilot relief valve is
faulty.
Gear pump is out
of order.
Pilot valve is
broken.
Replenish
specified oil to the
standard level.
Repair or replace.
Repair or replace.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair or replace.
Disassemble and
repair.
Clean pilot piping
interior or repair
piping.
Disassemble and
repair.
ͽ
;
Ϳ
ͽ
Is not main relief
valve faulty?
Does swing
control valve
spool move
lightly by hand?
Does swing
motor rotate?
Is gear pump
delivering oil?
Is not there oil
leakage from
pilot piping or is
not it clogged?
;
Ϳ
Is gear pump pilot
pressure within
standard level?
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
YES