Hyundai r35z-7 Workshop Manual page 192

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