jcb JS200 Service Manual page 436

Section E
95 - 1
Fault Finding
Table 1.
Symptom Cause
Internal damage to the
motor.
Internal damage to the
motor.
Relief valve in circuit not
set correctly.
Wear or damage to the
motor sliding surfaces or
to the high-pressure seal.
Oil hot and excessive
leakage in the motor.
Seizure of motor sliding
parts or circuit.
Damage or wear to oil
seal lip.
Damage or wear of the
shaft seal.
Abnormal pressure in the
casing.
9803/6400
Hydraulics
Slew Motor
External Inspection
Measure the oil drain
volume.
Open the motor inlet and
outlet ports and apply
2 2
20 kgf/cm (284 lbf/in )
pilot pressure to the
brake release port. Try
to rotate the shaft with
a torque of approx.
39.32 Nm (29 lbf ft).
Measure pressure.
Measure the oil drain
volume.
Measure the oil
temperature.
Check for any metallic
matter deposited in
motor drain oil or drain
2
filter. Apply a 30 kgf/cm
2
(427 lbf/in ) pilot pressure
to the brake release port
and try to rotate the shaft
with a torque of approx.
39.32 Nm (29 lbf ft).
Check the pressure in the
casing and measure the
drain volume.
Countermeasure
High possibility of
damage to the sliding
surfaces if the supply
volume is approximately
equal to the drain
volume. Dismantle and
inspect.
High possibility of
internal damage to the
motor if the supply shaft
does not rotate smoothly
when this torque is
applied. Dismantle and
inspect.
Reset to the prescribed
setting.
Leakage is too high if the
oil drain volume exceeds
5 l/min (1.1 gal/min).
Dismantle and inspect.
Reduce the oil
temperature.
If metallic matter is
discovered or the supply
shaft does not rotate
smoothly when torque is
applied, there is a high
possibility of internal
damage to the motor.
Dismantle and inspect.
Set the pressure in the
2
casing below 3 kg/cm .
2
(43 lbf/in ) Dismantle
and inspect if drain
volume is excessive.
Section E
95 - 1
Repair
Refer to Table 2.
Renew damaged parts
or renew the motor
assembly.
Refer to table 2.
Refer to table 2.
Repair or renew the
damaged parts. Renew
the motor assembly.
Renew the oil seals.
Repair the problem or
renew the motor
assembly.
Renew the oil seal.
Repair or renew the
damaged parts. Renew
the motor assembly.
Issue 2*