Hyundai HX130LCR Manual page 333

2) SWING SPEED IS LOW
Is MCV pilot
pressure same
on LH and RH
sides?
Single direction
Is the trouble in
one direction or
in both direction?
Both directions
Is Arm speed
within standard
value?
Is main relief
ⓒ
valve setting
pressure normal?
See Note 7
YES Does swing spool
move?
Is pilot piping
See Note 2
clogged or is it
NO
leaking oil?
Is MCV pilot
YES
pressure within
standard level?
See Note 2
NO
Is swing motor's
ⓐ drain rate within
standard value?
Is gear pump pilot
ⓑ
pressure within
standard level?
See Note 1
NO
Is MCV pilot
pressure within
YES
standard level?
See Note 2
YES
NO
YES
Clogged or oil
leak.
NO
Does swing spool
YES
move?
See Note 5
NO
NO
Check that pilot
piping is clogged
YES
or oil is leaking
from it?
Clogged or oil leak.
Is gear pump
delivering oil?
NO
Does the symptom
change when A1
YES
and A2 pump
discharge hoses
are exchanged?
Is gear pump
output pressure
within standard
NO
level?
See Note 1
6-10
Cause
Swing port relief Disassemble and
valve is faulty. repair or replace.
Swing control valve Disassemble
spool is stuck. and repair.
Clean pilot piping
interior or repair
piping.
RCV or shuttle Disassemble
valve is faulty. and repair.
YES
ⓐ
Swing spool is Disassemble
NO
stuck. and repair.
ⓑ
ⓒ
Swing motor is Disassemble
broken. and repair.
NO
RCV or shuttle Disassemble
valve is faulty. and repair.
Clean pilot piping
interior or repair
piping.
Pilot relief valve
YES
in gear pump is Disassemble and
defective. repair or replace.
Gear pump is Disassemble
NO
broken. and repair.
Main relief valve Main relief valve
faulty. pressure resetting
or repair.
YES
Hydraulic pump Disassemble
is broken. and repair.
Shuttle valve is Repair or replace.
NO
faulty.
YES
Pilot relief valve Repair or replace.
is faulty.
Gear pump is Repair or replace.
NO
faulty.
Remedy