TYM T233 HST, Service Manual

Page: 195 / 232

Problems Causes Countermeasures
2.Too low
rising speed of
lift
1)Above causes can also be
possible
Repair according to above instructions.
2) Too small a spool stroke in
control valve
Inspect,readjust,or replace link mechanism
if necessary.
3)Broken compensator spring
(unloading valve 1) in control
valve Replace spring.
4)Stuck poppet
(unloading valve 2)
Correct minor flaws with an oil stone
3.Lift lowers even
when adjust knob
is closed fully with
adjust Handle
(While engine is
stopped) 1)Stuck poppet Lap after disassembling,cleaning,repairing
flaws with oil stone
2)Poor valve seat Replace valve
3)Poor 0-ring Replace
4.Lift does not
lower
1)Slow-return-check valve
knob is turned to the lock
position Turn knob to fast position
2)Stuck poppet of slow-
Return-check valve
Lap after disassembling, cleaning,repairing
flaws with oil stone
9-34
3)Seized lift shaft Apply grease and repair or replace bushings
or shaft if necessary.
4)Stuck main spool Lap lightly after disassembling, cleaning,
and repairing flaws with oil stone or replace
as an assembly.
5.Too slow lift
lowering speed 1)Above mentioned causes
can also be possible. Repair or adjust according to instructions
mentioned above.
2)Insufficiently lowered
control lever Lower lever sufficiently
3)Excessively closed slow-
return check valve Open valve sufficiently
6.When hydraulic
control lever is
raised,relief,valve
beeps. 1) Maladjusted lever stopper
check valve Readjust lever stopper guide position
2) Poor link mechanism Inspect,readjust,repair,or replace link
mechanism if necessary.
7.Fluid
overheating
1)Excessively high working
pressure Inspect and adjust
2)Too high or low viscosity
of working fluid.
Replace with fluid of adequate viscosity.
3)Insufficient fluid Maintain specified level by replenishing