Komatsu Galeo PC138US-8 Shop Manual page 373

30 Testing and adjusting
Adjustment
a If the machine deviates, it can be corrected by
partially draining the oil discharged more from
the pump through the travel deviation adjusting
plug. (If the travel deviation is corrected by this
method, however, the pump discharge is
reduced. As a result, the travel speed, work
equipment speed in compound operation, and
relief pressure may lower.)
a If the machine deviates in the same direction
regardless of the travel direction, correct it
according to the following procedure. (If the
deviating direction of the machine depends on
the travel direction, the cause of deviation may
not be in the hydraulic pump. In this case,
carry out troubleshooting.)
a Only when the travel deviation is 200 mm or
less, it can be corrected by the following
method.
k
If the adjusting plug is loosened more than
the adjustment limit, high-pressure oil will
spout out. Take care extremely.
k
Lower the work equipment to the ground
and stop the engine. Operate the control
lever several times to release the residual
pressure from the piping, and then loosen
the oil filler cap of the hydraulic tank slowly
to release the residual pressure from the
tank.
1. Check the deviating direction and the locations
of travel deviation adjusting plugs (1) and (2).
(1): Right deviation adjusting plug (P1
q
pump)
(2): Left deviation adjusting plug (P2
q
pump)
a Loosen only the plug on either side for
adjustment. Do not loosen the plugs on
both sides.
PC138US, USLC-8
2. Fixing plug (3) with a hexagonal wrench (Width
across flats: 4 mm), loosen locknut (4).
a If the locknut is sealed with a vinyl tape,
remove that tape.
a Before loosening the locknut, make match
marks on it and pump case.
Loosening angle of locknut: Approx. 90 –
q
180°
3. Loosen plug (3) to adjust the travel deviation.
Quantity of adjustment of deviation per
q
turn of plug: 150 mm (Reference)
a The plug is fully tightened when shipped.
Adjust the deviation by the loosening
angle of the plug from the fully tightened
position.
a If the plug is turned together with the lock-
nut, tighten it fully again, then start adjust-
ment.
a The plug can be loosened by 2 turns
(720°) from the fully tightened position.
4. Fixing plug (3) with a hexagonal wrench,
tighten locknut (4).
3
Locknut: 2.9 – 4.9 Nm {0.3 – 0.5 kgm}
a After tightening the locknut, seal its hole
with a vinyl tape.
5. After finishing adjustment, check travel devia-
tion again according to the procedure for
inspection described above.
SEN02458-01
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