jcb 1CX, Service Manual

Page: 191 / 242

22 - 2
Typical Ram
(with dowelled piston head)
Dismantling and Assembly
Dismantling
Place the ram assembly on a locally manufactured
strip/rebuild bench.
Slacken the end cap 1 using a special spanner (see Service
Tools, Section 1) and remove the piston rod assembly from
the cylinder.
! !
WARNING
If air or hydraulic pressure is used to force out the piston
assembly, ensure that the end cap is securely fitted.
Severe injury can be caused by a suddenly released
piston rod.
HYD 1 - 2
Position the piston rod assembly on the bench in place of
the ram cylinder. Remove the piston head seals 2, 3 and 4.
Extract dowel 5 from the piston head using a metric screw
(M3) threaded into the extractor hole.
Note: Any attempt to remove the piston head without
removing the dowel will cause damage to both the piston
head and rod.
Remove piston head 6 from rod 7 using a special spanner
(see Service Tools, Section 1). Remove the piston head
internal 'O' ring 8.
Remove the end cap 1 from the piston rod and remove the
inner and outer seals 9, 10 and 11.
Ensure that all metal components are free from scoring,
nicks and burrs. A damaged rod will impair the life of the
inner rod and wiper seals.
Discard all seals and 'O' rings.
Assembling
Renew all seals and 'O' rings.
Thoroughly clean the threads of the piston rod, piston head,
end cap and cylinder using a wire brush. Use JCB
Cleaner/Degreaser to ensure that all threads are free from
grease, hydraulic oil and locking fluids. Allow 15 minutes for
the solvent to dry before applying JCB Activator.
Ensure that lubricants used during assembly do not come
into contact with locking fluids.
Use seal fitting tool (892/00334) to fit rod seals 9 and 10.
The size (diameter) and position of pins A is determined by
the diameter and radial width of the rod seal being fitted.
The pins are screwed into threaded holes in the tool body,
the spacing of the holes is designed to suit small or large
diameter rod seals.
1 Open the tool as shown at B and insert the new rod
seal, the seal must be fitted behind the two front pins
but in front of the rear pin as shown.
Note: Make sure the seals are fitted the correct way round,
as shown at P and Q.
2 Close the tool as shown at C. The seal must form a
reniform (kidney shape).
3 Before fitting the rod seals check the seal grooves are
free of contamination and sharp edges.
4 Locate the seal in the end cap groove, shown at D,
when the seal is in position, open the tool to release the
seal. Make sure the seal is correctly installed in its
groove and remove the tool.
5 Fit rod wiper seal 10 into seal groove. Make sure the
seal is correctly installed as shown.
Section E Hydraulics
9803/8550
Section E
22 - 2
Issue 4*
Rams
*
B
C D
A
161750
Q
P
153212
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