packing properly when retainer is tightened into
When installing the head on the rod, be
careful not to damage the packing.
(7) Install new backup ring (3. fig. 4-38) and
preformed packing (2).
(8) Assemble wear ring (8) on piston (1), and
install piston on the rod.
(9) Install the nut securing the piston to the
rod, and tighten per nut and bolt torque chart in
(10) Install seal assemblies (7) to the piston
(1). Refer to paragraph 4-8 f (14 through 20) for
Point "B" (fig. 4-33) will be at the 8.25 inch mark on
the expander assembly for this cylinder.
g. Packing Adjustment. Hydraulic cylinder
packing leakage can be caused by wear, cuts,
and/or distortion of the packing. If the cylinder
leaks around the rod, shims can be removed to
e. Inspection and Repair.
tighten the packing around the rod.
(1) Inspect the cylinder for scoring, pitting,
(1) Lower the bulldozer blade to the ground.
and wear. Replace a cylinder which cannot be
(2) Remove the bolts holding retainer (1, fig.
made serviceable with light honing.
4-40) to cylinder head.
(3) Pry on tap the retainer out far enough to
Do not weld on the cylinder assembly as
permit cutting and removing shims (2).
scoring may result from t h e bore
(4) Remove one shim at a time. If, after
removing two shims the cylinder still leaks, replace
(2) Replace all seals, packing, and wear rings.
(3) Inspect the rod end bearing for scoring,
damage, and wear. Replace as required.
(4) Inspect the piston rod for nicks, burrs,
pitting, distortion, and wear. Repair or replace a
damaged or distorted rod. Remove minor nicks and
burrs using a fine emery stone. Pitted, scored, or
worn rods may be repaired by metalizing or
chrome-plating and regrinding to original size. A
non-corrosive metal will be used to metalize shafts.
(1) Place retainer (6) packing rings (9) and
head (4) on the piston rod.
(2) Separate and oil all of the rings in packing
(9). Install one ring of packing at a time into head
(4) so the open part of the V is facing toward head.
Be sure rubber pressure ring (11) is located as
(3) Using retainer (6), tap the packing firmly
into place in the head.
(4) While holding retainer firmly seated
against packing, measure clearance (B, fig. 4-39)
between retainer and head with a thickness gage.
(5) Remove the head with the packing from
the piston rod, leaving the retainer on the rod.
(6) Install shims on the rod with a total
thickness of 0.010 inch to 0.01.5 inch less than the
measured clearance (B). This will preload the