Jeep cherokee 1989, Owner'S Manual

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Chapter
9
Brakes
Use a dial indicator to check disc
-
if the
reading exceeds the specified allowable limit, the
disc will have to be machined or replaced
Using a swirling motion, remove the glaze from the
disc surface with sandpaper or emery cloth
5 Brake disc
-
inspection, removal and installation
Inspection
Refer to illustrations and
1
Loosen the wheel lug nuts, raise the vehicle and support it securely
on jackstands. Remove the wheel.
2 Remove the brake caliper as described in Section 3. It's not
necessary t o disconnect the brake hose. After removing the caliper
mounting pins, suspend the caliper out of the way with a piece of wire
as shown in illustrations
Don't let the caliper hang by the hose
and don't stretch or twist the hose. Reinstall t w o of the lug nuts t o
hold the disc in place
models only).
3
Visually check the disc surface for score marks and other damage.
Light scratches and shallow grooves are normal after use and may not
always be detrimental to brake operation, but deep score marks
over
0.01 5-inch (0.38
-
require disc removal and refinishing by an
automotive machine shop. Be sure t o check both sides of the disc.
If pulsating has been noticed during application of the brakes, suspect
disc
Be sure t o check the wheel bearings t o make sure they're
properly adjusted.
4 To check disc place a dial indicator at a point about 112-inch
from the outer edge of the disc (see illustration). Set the indicator to
zero and turn the disc. The indicator reading should not exceed the
specified allowable
limit. If it does, the disc should be refinished
by an automotive machine shop. Note: Professionals
facing of brake discs regardless of the dial indicator reading (to pro-
duce a smooth, flat surface that will eliminate brake pedal pulsations
and other undesirable symptoms related to questionable discs). A t the
very least, if you elect not to have the discs resurfaced, deglaze them
with sandpaper or emery cloth (use a swirling motion to ensure a
directional finish) (see illustration).
5 The disc must not be machined t o a thickness less than the speci-
fied minimum refinish thickness. The minimum (or discard) thickness
is cast into the inside of the disc (see illustration). The disc thickness
can be checked with a micrometer (see illustration).
Removal
6 If the vehicle is a remove the t w o lug nuts that were installed
t o hold the disc in place, then slide the disc off the hub. If the vehicle
is a
refer t o Chapter 1, Front wheel bearing check, repack and
adjustment for the hubldisc removal procedure.
The minimum thickness is cast into the inside
of the disc
Use a micrometer to measure disc thickness at
several points
The Motor Manual Guy