Hyundai HX145LCR Manual page 376

4) 4) BOOM, ARM OR BUCKET POWER IS WEAK 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?
See Note 7
NO
5) 5) ONLY BUCKET OPERATION IS TOTALLY IMPOSSIBLE ONLY BUCKET OPERATION IS TOTALLY IMPOSSIBLE
Is MCV pilot
YES
pressure within
standard level?
See Note 4
Is LH travel
possible?
Does the
symptom change
when main relief
NO
valves are
exchanged?
YES
Is cylinder
YES
internal leakage
within standard
level?
NO
NO
YES
Does the
symptom change
YES
when port relief
valve is replaced
with other valve?
NO
NO
YES
Does the
symptom change
YES
when hydraulic
pump's discharge
NO
hoses are
exchanged?
6-21
Cylinder is faulty.
Port relief valve is
faulty.
Main relief valve
is defective.
Port relief valve is
defective.
YES
MCV spool is
Does control
stuck.
valve spool
move?
Cylinder interior is
NO
See Note 5
broken.
RCV is faulty.
Main relief valve
is faulty.
Hydraulic pump is
broken.
Cause
Remedy
Check according
to the procedure
in Item "Speed is
low".
Disassemble
and repair.
Adjust pressure,
repair or replace.
Adjust pressure,
repair or replace.
Cause Remedy
Disassemble
and repair or
replace.
Disassemble
and repair.
Disassemble
and repair.
Disassemble
and repair.
Adjust pressure,
repair or
replace.
Disassemble
and repair.