Specifications

82
the piston rod. When the lift lever is pushed, the circuit between the lower part of the
lift cylinder piston and the oil tank is opened, and the piston begins to descend due to
the weight of the piston rod, lift bracket, forks, etc. In this case, the oil returning to the
control valve is regulated by the flow regulator.
When the tilt lever is operated, the hydraulic oil from the main pump reaches one
side of the piston to push it. The oil pushed by the piston returns to the oil tank through
the control valve.
6.8 Troubleshooting
Problem
Possible cause
Remedies
Gear pump
can not be
pressurized.
Parts worn.
Disassembly, repair or replace
parts.
Blocked oil pipe.
Make the oil pipe through.
Blocked oil tank or filter.
Clean dirty or replace oil.
Too high oil stickiness or oil
temperature.
Use recommended oil.
Noisy or
undulate
pressure.
Blocked oil filter.
Clean dirty.
Lower oil level.
Add oil up to specified oil level.
Air entering in resulting from
loose suction connections.
Retighten each connection.
Gear precision is reduced.
Replace gear or shave.
Control valve
leaks.
O-ring seal (ends of valve body)
broken down.
Replace O- ring seal.
O-ring seal (connections of valve
body) broken down.
Replace O- ring seal.
Spool can not
be reset.
Return spring become deformed.
Replace return spring.
There is dirty between valve body
and spool valve.
Clean.
Valve body deformed with the too
tight coupling bolt.
Retighten coupling bolt.
The pressure
of the relief
valve is not
right.
Pressure regulating spring
deformed.
Replace pressure regulating
spring.
Cone valve is worn.
Replace cone valve.
Lock nut is loosen.
Tighten and lock.
Outlet port is block up.
Clean.
The lower
slippage of
the mast is
too large.
The clearance between valve
body and spool becomes large.
Repair or renew spool.
The spool isn’t in neutral position.
Make the spool in neutral
position.
Cone valve is worn or seized by
dirt.
Replace cone valve or clean
dirty.