Parts Identification
& Manual Service
18/40
Issue 1.0
TROUBLE
POSSIBLE CAUSE
SOLUTION
Oil motor stalls at
bottom (no unusual
heat problems).
▪
Fluid
pump
piston
seat
unthreaded.
▪
Valve sticking or oil motor trip
rod shifter assembly separated.
▪
If connecting rod is okay,
remove cylinder head plug and
pop valve down. Replace plug
and start machine. If machine
cycles up and stops at bottom
again, then problem is piston
seat on fluid pump. Check
piston seat. Repair or replace
as necessary. If piston seat is
okay and problem does not
change, check oil motor.
▪
Remove valve and check for
scratches and rough movement
when sliding it up and down.
Replace valve and spool in this
condition. Check trip rod for
possible separation and spool in
this condition. Check trip rod for
possible separation.
Oil motor stalls at
top
(no
unusual
heat problems).
▪
Valve sticking.
▪
Broken spring retainer (valve
rod assembly).
▪
Broken spring or valve rod.
▪
Air in hydraulic motor.
▪
Air in fluid pump
▪
Remove valve and check for
scratches and rough movement
when sliding it up and down.
Replace valve and spool in this
condition.
▪
Replace valve rod assembly.
▪
Replace valve rod assembly
▪
Reset
valve.
Purge
Air,
generally accomplished by low
pressure cycling of motor/pump
assembly for 5-10 minutes.
Check
for
causes
of
air
introduction:
o
Loose fittings in tank.
o
Loose fittings on hydraulic
pump.
o
Loose hose connections.
o
Low oil in reservoir.
▪
Stall at top can occur randomly
when fluid pump picks up air.
Reset valve. Avoid air in the
fluid pump.