Hyundai r35z-7 Workshop Manual page 201

6 6 . ATTACHMENT SYSTEM
1) BOOM OR ARM ACTION IS IMPOSSIBLE AT ALL
Are other
YES
attachments
operatable?
Are LH/RH travel
operations
possible?
Inspect oil
volume in
NO
hydraulic oil tank.
YES
Is MCV pilot
YES
pressure within
standard level?
NO
Is gear pump pilot
YES
pressure within
NO
standard level?
YES
Remove dust plug
under engine
flywheel and
OK
check if coupling
element particles
are not present.
Short
5-18
YES
Port relief valve is
Does the
symptom change
faulty.
when port relief
valve is replaced
with other valve?
NO
Inspect if pilot
piping is not
OK
clogged or oil is
Pilot valve is
not leaking from
faulty.
the piping.
Pilot relief valve is
faulty.
Is gear pump
delivering oil?
Gear pump is
NO
broken.
OK
Hydraulic pump is
Disassemble
broken.
main relief valve
and check if it is
not irregular.
Main relief valve
Faulty
is defective.
Particles present
Coupling at pump
connection is
broken.
YES
Cylinder interior is
Does control
broken.
valve spool move
lightly by hand?
Control valve
NO
spool is stuck.
Cause Remedy
Disassemble
and repair or
replace.
Disassemble
and repair.
Disassemble
and repair or
replace.
Disassemble
and repair.
Disassemble
and repair.
Disassemble
and repair or
replace.
Disassemble
and repair.
Replenish
hydraulic oil.
Disassemble
and repair.
Disassemble
and repair.