Komatsu 830E Shop Manual page 394

3. Inspect condition of brake caliper thoroughly
before installing linings.
a. Inspect for evidence of fluid leakage. If
present, brake must be removed for disas-
sembly, inspection and repair.
b. Inspect condition of dust shields. These
should be soft and pliable, and show no evi-
dence of hardening of material, rupture, etc.
Where replacement is necessary, removal
and disassembly of brake for inspection is rec-
ommended to insure that dirt has not entered
piston cavity through a ruptured seal.
c. Inspect condition of tubing and fittings. If leak-
age is evident, correct or replace fittings as
necessary.
Do not rub or press dust shield directly over sharp
edge around piston cavity. This may cause dust
shields to be cut.
d. Wipe brake housing and lining retaining plates
clean before installation of new linings. If a
petroleum base cleaning fluid is used, such as
diesel fuel, use sparingly on dust shields and
wipe dry after cleaning.
J6-14
FIGURE 6-17. PISTON RETRACTION TOOL
NOTE: When installing new linings to be used against
a worn disc, useful lining life will be shortened by the
depth of the disc wear, since the lining must advance
this additional distance before braking force is
effective. In addition, the uneven wear on the disc face
will accelerate lining wear.
Rockwell Armature Speed Rear Disc Brakes
4. Inspect discs for wear (Figure 6-18). Place a
straight edge across face of disc and measure
from straight edge to worn face. It is recom-
mended that the disc be replaced when this mea-
surement is 0.06 in. (1.52 mm) each side of disc
or at a minimum worn thickness of 0.88 in. (22.3
mm). It may be difficult to use a straight edge on
the back surface of the disc so a visual compari-
son may be used with that of the front. Normally,
wear will be the same on both sides.
J06020