jcb JS200 Service Manual page 437

Section E
95 - 2
Fault Finding (cont'd)
Symptom Cause
Wear or seizure of the
motor sliding surfaces.
Relief valve in the circuit
is not set correctly.
Internal damage to the
motor.
Large amount of air
mixed in the oil.
Loosening of bolts or
pipes
O-ring is damaged
Seal face is damaged.
Bolts are loose.
Table 2.
No.
a Wear of the sliding surface of balance plate 21.
b Damage to sliding surface of cam plate 6.
c Damage to sliding surface of the piston assemblies 8.
d External wear to the piston assemblies 8.
e Wear to piston bores in cylinder assembly 24.
f Damage to Teflon ring 19 or 'O'-rings 52.
9803/6400
Hydraulics
Slew Motor
External Inspection
Open motor inlet and
outlet ports and apply 20
2 2
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 relief pressure.
Check if any metallic
matter is deposited in the
motor drain oil or drain
filter.
Check the oil in the tank
and motor casing.
Check if the piping
connections, attachment
mounting bolts, motor
attachment bolts or other
bolts are loose.
Check the bolt tightness.
Part Inspected
Countermeasure
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.
High possibility of
internal damage to the
motor if metallic matter
is discovered.
Dismantle and inspect.
Thoroughly bleed the air.
Tighten to the specified
torque.
Tighten the bolts to the
correct torque.
Repair or renew the part
Repair the part or renew the motor.
Repair the part or renew the motor.
Repair the part or renew the motor.
Renew the motor.
Renew the part.
Section E
95 - 2
Repair
Inspect the parts and
bearing according to
Table 2 a-e and renew
any defective parts.
Repair or renew
damaged parts. Renew
the motor assembly.
Renew O-rings.
Repair seal face or
renew.
Repair
Issue 2*