XLB-4725A
4-10
4. Remove headstock (2). Remove and discard o-ring (11), backup ring (12), and
seal (13). Remove bushing (14) and wiper (15). Discard wiper.
5. Inspect the cylinder rod (3) for scratches or pits. Pitting in the base metal is not
acceptable. Wear indications that catch the fingernail, but do not extend into the
base metal nor extend more than 1/2 inch along the rod length are acceptable if
they will not cut the seal material. The chromium plating must not be worn
through. Replace the cylinder rod if not acceptable by these inspection criteria.
6. Inspect the headstock (2). Check the inside bore for scratches; deep scratches or
cracks are unacceptable. Check the bore for polished wear surfaces. Polishing
indicates uneven loading. Check the bore for out-of-roundness. If the bore is
more than 0.007 inch out-of-round, replace the head. Seal groove damage is un-
acceptable. Replace the headstock if these conditions are not met.
7. Inspect piston (6). Check the outside surface for scratches; deep scratches are
unacceptable. Check the outside surface for polished wear surfaces. If polishing
is noticed, check the piston for out-of-roundness. If out-of roundness exceeds
0.007 inch, replace the piston. Seal groove damage is unacceptable. Replace the
piston if these conditions are not met.
8. Inspect cylinder housing (4) for scratches or pits. Pits or scratches that are deep
enough to catch the fingernail are not acceptable. Scratches that catch the finger-
nail, but extend less than 1/2 inch along the tube length, are acceptable providing
they are not sharp enough to cut the seals. Replace the cylinder tube if these
conditions are not met.
Cylinder Assembly
1. Lubricate headstock (2, Figure 4-6), wiper (15), seal (13), backup ring (12), and
o-ring (11) with hydraulic fluid.
2. Twist seal (13) into a ‘C’ shape and seat it in mating groove of headstock (2).
3. Seat wiper (15), backup ring (12), and o-ring (11) in mating groove of headstock
(2). Make sure the back-up ring is installed above the o-ring. Use brass tools or
plastic tools to avoid seal groove damage during installation. Scratching the seal
grooves may cause by-pass leakage. Allow the assembled headstock to sit one
hour for the seals to regain their original shape.
4. Lubricate piston (6) and o-rings (8 and 9) with hydraulic fluid.
5. Install wear ring (7). Allow the assembled cylinder head to sit one hour for the
seals to regain their original shape.
6. Thoroughly rinse the inside of cylinder housing (4) with a high-pressure rinse
and wipe with lint free cleaning cloths.
7. Install the headstock (2), bushing (14), stop sleeve (10), piston (6) and nut (5 )
onto the cylinder rod (3). Tighten the nut from 100 to 120 lb-ft (136 to 162
N
·m).
8. Apply anti-seize to the headstock threads and installed o-ring (11).
9. Coat the cylinder rod with hydraulic fluid and insert the rod into the cylinder
housing. When inserting headstock (2) make sure that static o-ring (11) does not
extrude from the o-ring groove. Be careful not to nick the seals as they enter the
cylinder housing.
10. Screw headstock into the cylinder housing and tighten for a snug fit of the wiper
(15) on the cylinder rod (3).
11. Press in new bearings (1).
