5 Series E39 523i (M52TU) SAL
VK-23, Kiehne
Baugruppe/Group: 34
34 02 96 (134)
weltweit/all
countries
11/1996
Front brakes squeal
E39 except 540i
Situation:
Brake squealing during light initial braking or shortly before the vehicle comes to a complete
stop basically results from high-frequency vibrations due to the friction occurring between
the brake lining and the brake disc (stick/slip effects). Acoustic perception takes place via
the resonating brake and axle components.
To counteract brake squealing on the front axle, "tangential, diagonally ground" linings have
been used on the E39 since week 50/95, i.e. the friction surfaces of the linings installed on
the piston side are touch-ground at an angle to the carrier plate and not parallel, as was
previously the case. Grinding the linings diagonally makes them running-direction
dependent and requires them to be installed accordingly.
In week 45/96 altered brake caliper brackets, brake linings and a modified housing
retaining spring were introduced in series production for technical production reasons.
These linings are also "diagonally ground" on the piston side and running-direction
dependent.
For logistical reasons, the offer of the previously used brake caliper brackets for
replacement by the Parts department has been eliminated as of the introduction of the
production change. Now only the "new", changed brake caliper brackets will be offered.
Note: As a completely different front-axle brake is installed on the 540i, it is not affected.
Procedure:
1.
In the case of repairs, only "diagonally-ground" linings are to be installed. Any "parallel-
ground" brake linings which may still be in stock are to be sent back via the usual parts
claims channels.
2.
To prevent reduced comfort, always ensure the proper production-related assignment
of the brake linings to the brake caliper bracket when installing new brake linings.
Brake caliper brackets manufactured before the production change in week 45/96
may only be paired with brake linings marked with a white dot on the carrier plate of
the stub-side lining.
Brake caliper brackets manufactured after the production change in week 45/96 may
only be paired with the brake linings adapted to them (not marked with a white dot).
Brake caliper bracket
Brake linings
Marking
Before the production
change (please refer to Fig.
S3496003)
Diagonally-ground linings
White paint dot on the carrier
plate of the stub-side lining
(can also be seen from
outside when mounted)
After the production change
(please refer to Fig.
S3496004)
Diagonally-ground linings
(brake linings adapted to the
modified bracket)
Additional weights on the
brake caliper bracket. Linings
without marking
SI Front brakes squeal E39 except 540i
BMW AG - TIS
14.02.2013 02:25
Issue status (12/2007) Valid only until next DVD is issued
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