Brakes - Body Vibration/Steering Wheel
90bmw18 Group 34 BrakesBulletin Number 34 05 90 (3118)
Woodcliff Lake, NJ October 1990 Service Engineering
SUBJECT: Brake Induced Steering Vibration
MODELS: E24, E28, E30 (equipped with Jurid 506 brake pads)
Situation: Some vehicles equipped with Jurid 506 brake pads may exhibit a brake induced steering vibration (usually when decelerating in the 60 --> 40 mph range), especially when the brakes are hot. When checking the brake discs for runout and thickness variation the discs are usually found to be within specifications.
The cause for this complaint was found to be that some brake pads were produced in production lots that were excessively hardened. These hard pads would exaggerate any surface differences in the brake disc material, causing the vibration.
Later production pads are being manufactured under a more controlled process, to prevent the pads from being over-hardened. These pads are commonly referred to as Jurid 5061 pads, and can be differentiated by the * symbol on the back of the pad.
Correction: When a vehicle equipped wfth Jurid 506 pads has a complaint of brake induced vibration, the front pads only must be replaced wfth Jurid 506* pads.
The brake discs should be checked for thickness using BMW special tool 88 88 6 341 280, and reground if the disc thickness is at least 0.5 mm more than the machining limit stamped on the disc.
NOTE: It is not necessary to remove large amounts of material when grinding the disc. Removal of 0.15 mm of material on each side during the rough cut (fast speed) and 0.05 mm of material on each side during the finish cut (slow speed) is usually sufficient. Removal of excess material only shortens disc life.
If there is not sufficient material remaining to grind the discs, they must be replaced.
Warranty
Status: Covered under the terms of the BMW New Car Limited Warranty.
Defect code: 34 11 00 21 00
Labor operations:
Replace front pads 34 11 000
R&R front discs: E30 34 11 613
E24, E28 34 11 610
Grinding both discs 34 11 667
(only if discs are not replaced)
Any questions regarding warranty coverage should be discussed with your District Service Manager.