Takeuchi TB 250 - Machine Slews, but Overruns When Slewing Stops or Cannot be Stopped

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5
SLEWING
TROUBLESHOOTING
The machine slews, but overruns a lot when slewing stops, or slewing cannot be stopped
1
Is the amount of overrun
when slewing stops with-
in specs?
W
ithin specs
Normal
Out-of-specs
2 Check the pilot valve
Faulty
Repair
or replace the pilot
valve
Normal
3
Check
the spool opera-
tion
Faulty
Repair
or replace the housing
block
Normal
4
Check
the check valve of
the slew brake valve
Faulty
Repair
or replace the brake
valve
Normal
5 Check the slew pr
essure
Pressure too low
Adjust the slew relief valve
pressure
Adjust to set pressure
Pressure does not rise
Repair or replace the relief
valve
1. Is the amount of overrun when slewing stops within
specs?
“2. Service data, Performance criteria”
2. Check the pilot valve
Check if the spool of the pilot valve returns to the neu-
tral
position when the operation lever (slew) is released
after operation. Disconnect the hose connecting the
pilot valve and control valve (slew block) from the con-
tr
ol valve. Fit the pressure gauge to the hose just dis-
connected.
• Operate the lever (slew) and then release it to read
the pressure gauge.
• If the pressure is zero, the pilot valve is normal.
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