Takeuchi TB 250 - Boom Swing; Swing Cylinder Does Not Move

5-39
5
TROUBLESHOOTING
BOOM SWING
BOOM SWING
Swing cylinder does not move
1
Check the operation of
actuators other than of
the swing cylinder
Normal
2
Check
the spool opera-
tion
Faulty
Repair
or replace the housing
block
Normal
3 Check the linkage
Faulty
Adjust, r
epair or replace
Normal
4
Check
the anti-cavitation
valve
Faulty
Repair
or replace the anti-cav-
itation valve
Normal
5 Check the swing cylinder
Faulty
Repair
or replace the swing
cylinder
1. Check the operation of actuators other than of the
swing cylinder
Determine if only the boom swing cylinder is faulty by
checking the operation of actuators for the devices
listed in the table on the right. If one of them is faulty,
check the main relief valve and the hydraulic pump
(main).
“5-5”
2. Check the spool operation
• Spool stroke: 8 mm
• If the spool is sticking, try to take it out.
If it can’t be taken out or is scratched, replace the
housing block.
Note that the faulty spool operation could be caused
by the loosened bolt used for the return spring.
Lever to operate
Device to check
Relief valve Pump
Left travel
TB228, 235: R1 TB228, 235: P1
TB250: R2 TB250: P2
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