jcb JS130, Service Manual

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78 - 2
Section E Hydraulics
9803/6410
Section E
78 - 2
Issue 1
Hydraulic Rams
Fault Finding (cont’d)
Item Symptoms Related Parts Trouble Treatment
Packing rubber is perished. The packing life or hydraulic oil
deterioration and high temperature are
possible reasons.
1 Renew hydraulic oil.
Rod packing 2. Check the hydraulic oil temperature.
(Buffer ring, (Below 80 C is advisable).
U-ring)
3 Check if high temperature locally.
Lip is deficient all around. Renew.
It is possible that abnormally high pressure
is working on the packing.
1 Check the operation pressure, cushion
pressure.
2 Part which is attached to the buffer ring
may be abnormal. Inspect the buffer
ring.
The protrusion of the heel of the As a rule, renew the rod packing at the
packing is excessive. same time. (It is desirable to renew parts
1 Piston rod which are attached to the buffer ring at the
oil leakage Back up ring same time).
It is possible that abnormally high pressure
is the cause. Check the same as above
(heel of packing protruding).
Foreign matter is biting into the Remove the foreign matter.
Wiper ring lip. The lip is damaged.
There is also other abnormal Renew.
damage.
Wear is excessive and the clearance Renew.
with piston rod exceeds the
*maximum permissible value.
Bushing (*Refer to maintenance standards
for maximum permissible value.)
Large scratch on the sliding part. Renew.
Also inspect the piston rod.
Scratches, rust on the seal Remove scratch, rust with oil stone. If it
Cylinder head attachment parts. cannot be repaired, renew the cylinder
head.