Merkur Scorpio V6-179 2.9L (1989)
Technical Service Bulletin # 90114
Date: 900523
Brakes - Shudder During Light Application
Article No. 90-11-4
BRAKES-FRONT DISC-SHUDDER DURING LIGHT
BRAKE APPLICATION
STEERING-STEERING WHEEL NIBBLE-DURING LIGHT BRAKE APPLICATION
VIBRATION-SHUDDER OR STEERING WHEEL NIBBLE-DURING LIGHT BRAKE APPLICATION
MERKUR:
1988-89 SCORPIO
ISSUE:
A body vibration, steering wheel nibble, or shudder/pulsation in the brake pedal during light brake pedal application may be caused by
uneven wear of the disc brake rotors. The old spindle carrier assembly used a "slip-fit" wheel bearing on the spindle shaft. The spindle
carrier has been revised to a "press-fit" wheel bearing design. This prevents uneven disc wear by improving the lateral runout caused by the
wheel bearing to spindle shaft fit.
ACTION:
Install new spindle carrier assemblies and front rotors. On cars built before 3/01/89 install new improved outer control arm to stabilizer
bar bushings. Refer to the following procedure for service details.
NOTE:
WHEN LOOKING FOR A BRAKE SHUDDER, IT IS IMPORTANT TO DIAGNOSE THE CONDITION ACCURATELY BEFORE
TAKING CORRECTIVE ACTION. IT IS IMPORTANT TO FOLLOW THIS REPAIR PROCEDURE CLOSELY TO RESOLVE THE
CONCERN.
Pre-Road Test Inspection
1.
Check the tire pressure. Make sure the tires are set at 32 PSI.
2.
Inspect the front and rear tires and wheel assemblies for:
^
Damage
^
Uneven tread wear
^
Tire side wall damage
^
Flat spots on the tire tread
3.
Correct any damage to the tires and wheels before the road test.
Road Test
1.
Drive the car up to 55 mph (88.5 km/h) on a smooth, level road surface. Once the car reaches the desired speed, place the transmission in neutral
and allow the car to return to rest without braking. Does the steering wheel nibble?
^
If YES - This usually indicates wheel assembly imbalance. This condition must be corrected before continuing. Refer to the 1989 Scorpio
Shop Manual, Section 11-01 for tire and wheel service details.
^
If NO - Continue with Step # 2.
