TROUBLE SHOOTING
PROBLEM
Loader drops with control
valve spool in %entered”
position (no external oil
leakage evident).
Note: A gradual drop over an
extended period is a normal
condition.
Control valve spool(s) will
not return (position) to
‘centered” position.
External hydraulic fluid
leakage.
POSSIBLE CAUSE
Cylinder piston assembly
leakage.
Control valve internal
.leakage. .
Control lever/linkage
binding.
Control valve spool
centering spring broken.
Control valve spool binding
in valve body spool bore.
Loose hydraulic connection.
Defective hydraulic hose,
tubeline, adaptor fitting or
adaptor fitting ‘0’ ring.
Control valve ‘0’ rings
defective.
Control valve spool or body
damaged/or worn.
Cylinder rod packing set
leakage.
CORRECTION
Check cylinders for leakage
as described under cylinder
leakage tests.
Replace control valve &
recheck.
Determine origin of binding
and repair.
Replace centering spring.
Refer to valve service
procedure.
Disassemble valve for
inspection and repair. Refer
to valve service procedure.
Tighten loose connection.
Check for origin of oil leak
and replace defective part.
Replace defective ‘0’ rings.
Replace control valve.
Perform cylinder leakage
test for rod packing set as
described under cylinder
leakage tests.
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