Hyundai r35z-7 Workshop Manual page 204

4)
BOOM, ARM OR BUCKET POWER IS WEAK
Is relief pressure
YES
in port relief
valve within
standard level?
Is relief pressure
in main relief
valve within
standard level?
NO
5)
ONLY BUCKET OPERATION IS TOTALLY IMPOSSIBLE
YES
Is MCV pilot
pressure within
standard level?
NO
Is cylinder
YES
internal leakage
within standard
level?
NO
Does the
symptom change
when port relief
valve is replaced
with other valve?
5-21
YES
NO
YES
Does control
valve spool
move smoothly
NO
by hand?
Cause
Check according
to the procedure
in Item "Speed is
low".
Cylinder is faulty. Disassemble
and repair.
Port relief valve is Adjust pressure,
faulty. repair or replace.
Main relief valve Adjust pressure,
is defective. repair or replace.
Cause
Port relief valve is Disassemble
defective. and repair or
replace.
YES
Cylinder interior is Disassemble
broken. and repair.
Control valve Disassemble
NO
spool is stuck. and repair.
Pilot valve is Disassemble
faulty. and repair.
Remedy
Remedy