Aerostar AWD V6-183 3.0L (1991)
Wheel Bearing: All Technical Service Bulletins
Front Disc Brakes - Popping/Clunking Noise
Article No.
93-25-5
12/08/93
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BRAKES - FRONT DISC - "POPPING" NOISE AND "CLUNKING" WHEN BRAKING AND TURNING - NON-E4WD VEHICLES BUILT
FROM 4/1/91 THROUGH 12/31/92
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NOISE - "POPPING" AND "CLUNKING" FROM FRONT BRAKES WHEN BRAKING AND TURNING - NON-E4WD VEHICLES BUILT
FROM 4/1/91 THROUGH 12/31/92
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VIBRATION FELT IN FLOOR WHEN BRAKING AND TURNING - NON-E4WD VEHICLES BUILT FROM 4/1/91 THROUGH 12/31/92
LIGHT TRUCK:
1991-93 AEROSTAR
This TSB article is being republished in its entirety to correct the part number for the brake pad kit.
ISSUE:
A "popping" or "clunking" noise may be heard and a floor board vibration may occur when braking and turning. The noise and/or vibration may be
caused by a poorly finished edge on the inner brake pad backing plate and by slightly loose wheel bearing end play. A burr on the inner brake pad causes
the pad to stick in the spindle shoe slot during braking, then, when the steering is operated, the rotor moves abruptly (due to excessive wheel bearing end
play) and dislodges the pad in the shoe slot. When the pad becomes unstuck, it "pops" sharply back into place in the shoe slot, making the noise and/or
vibration.
ACTION:
Reset wheel bearing end play and remove burr(s) from the ends of the inner brake pad backing plates where they slide in the spindle shoe slots. Refer to
the following procedure for service details.
1.
Road test the vehicle to confirm that the "popping" or "clunking" noise occurs only while braking and usually while turning.
2.
Raise the front of the vehicle and remove the front brake calipers. Refer to the Service Manual, Section 06-03, for the complete removal
procedure:
a.
Remove the front wheels
b.
Use an eight-inch "C" clamp to bottom the caliper piston in its bore.
c.
Remove the caliper pins and remove the caliper from the rotor. Secure the caliper so that it does not hang by the brake hose.
d.
Remove the brake pads and remove the anti-rattle clips from the brake pads.
3.
Reset wheel bearing end play. Refer to the Service Manual, Section 04-01A:
a.
Remove the grease cap from the hub and wipe any excess grease from the end of the spindle.
b.
Remove the cotter pin and retainer and loosen the adjusting nut three (3) turns.
c.
While turning the rotor in the opposite tightening rotation direction to seat the bearings, tighten the adjusting nut to 23-34 N-m (17-25 lb.ft.)
using a torque wrench.
d.
Loosen the adjusting nut 1/2 turn.
e.
Retighten the adjusting nut to 2.0-2.3 N-m (17-25 lb.in.) using a torque wrench.
f.
Place the retainer on the adjusting nut so that the castellations on the retainer are aligned with the cotter pin hole.
NOTE:
DO NOT TURN THE ADJUSTING NUT TO ALIGN THE RETAINER WITH THE COTTER PIN HOLE. IF NECESSARY, REMOVE THE
RETAINER FROM THE NUT AND RE-INDEX IT. REPEAT THIS AS OFTEN AS NECESSARY UNTIL THE HOLE IS LINED UP.
g.
Install a new cotter pin (N642569-S361) and reinstall the grease cap.
