Front/Rear Brakes - Pulse/Shudder/Squeal

91amcjeep04

NO.: 05-51-91 Rev. A

GROUP: BRAKES

DATE: June 17, 1991


SUBJECT: BRAKE SHUDDER/PULSE/NOISE


MODELS:

1990- >> 1991 << (BD) TALON


THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 05-51-91, DATED 02/25/91 WHICH SHOULD BE REMOVED
FROM YOUR FILES. ALL REVISIONS ARE HIGHLIGHTED WITH >> ARROWS <<.


SYMPTOM/CONDITION:

Some 1990 and >> 1991 << Talon vehicles may experience a shudder/pulse/squeal from the front brakes or squeal from the rear brakes. The following parts are now available to help reduce these complaints.


DIAGNOSIS:

Determine if noise is coming from the front or rear brakes. If the noise is coming from the rear brakes, replace the rear brake pads as outlined in appropriate service manual. If shudder/pulse/noise is coming from the front brakes, continue with this repair procedure.


PARTS REQUIRED:


DESCRIPTION APPLICATION PART NUMBER

FRONT BRAKES


Pad and Shim Kit 1990 VIN prior to >> MB895168 <<
(replaces pad kit LE022700

MB587284 & MB668398)

Pad and Shim Kit 1990 VIN after >> MB895072 <<
(replaces pad kit LE022701
MB699174 & MB858583) >> ALL 1991 <<


REAR BRAKES


Pad Kit 2WD Vehicles MB857732

Pad Kit 4WD Vehicles MB857729


>> REPAIR PROCEDURE <<

NOTE: FAILURE TO FOLLOW REPAIR PROCEDURES WILL CAUSE BRAKE SHUDDER/PULSE TO REOCCUR.


This repair involves checking the front disc rotors for thickness variation, runout, phasing the rotor to the hub, and or replacement of brake pads.

On vehicle, disc rotor runout is the combination of the individual runout of the hub face and the runout of the disc.

1. Remove the front wheel and reinstall the disc to the hub. Install the lug nuts and tighten to 120-140 N-m (87-101 ft.lbs.).


FRONT DISC BRAKES

CHECKING DISC ROTOR FOR RUNOUT AND THICKNESS VARIATION AND OR PHASING DISC ROTOR TO HUB:

1. Thickness variation measurements of disc should be made in conjunction with runout.


2. Mount a dial indicator on the steering arm. Dial indicator plunger should contact disc (braking surface) approximately 5 mm (0.2 in.) from edge of the disc.

3. Check lateral runout. Runout should not exceed 0.08 mm (0.0031 in.).

4. If runout is in excess of this specification, check the lateral runout of the hub face.

5. Before removing disc, make a chalk mark across both the disc and one wheel stud, on the high side of runout, so you will know how the disc and hub was originally mounted. Remove disc from hub.

6. Clean hub surface before checking. Install a dial indicator on steering knuckle. Position stem so it contacts the hub face near the outer diameter. Care must be taken to position stem outside the stud circle but inside the chamfer on the hub rim.

7. Runout should not exceed 0.08 mm (0.0031 in.). If hub runout exceeds this specification, hub must be replaced.

8. If hub runout does not exceed this specification, install disc on hub with chalk marks two (2) wheel studs apart. Tighten nuts in the proper sequence and torque to specifications.


NOTE: THERE ARE FIVE (5) PHASE POSITIONS TO INSTALL THE DISC TO THE HUB (EXCEPT ABS EQUIPPED VEHICLES WHICH CANNOT BE ADJUSTED).


9. Check runout of the disc to see if runout is now within specifications. If runout exceeds specifications, replace disc.

10. Measure thickness at eight (8) or more equal points with a micrometer at a radius approximately 5 mm (0.2 in.) from the edge of disc.

11. If thickness measurements vary by more than 0.15 mm (0.0059 in.) replace the disc. If cracks or burn spots are evident in the disc, replace the disc.

12. Check runout on the new disc to verify it is within specifications, 0.08 mm (0.0031 in.).

13. Repeat the repair procedures for other side of vehicle.


If the disc and hub are within specifications, replace the front pads.

Refer to the appropriate service manual for front disc rotor, front hub assembly,
front disc pads installation procedures.


POLICY: Reimbursable within the provisions of the warranty.


>> TIME ALLOWANCE <<
Labor Operation No. 05-70-22-92 0.8 Hrs.
Replace Rear Brake Pads

05-70-22-93 1.8 Hrs.
Check Disc Rotors, Hubs and
Replace Pads and Rotors as Required

05-21-09-90/91 1.0 Hrs.
Replace Front Hub Right or Left


FAILURE CODE: 68 - Noisy