900 S Hatchback L4-2290cc 2.3L DOHC EFI (1997)
Brake Rotor/Disc: All Technical Service Bulletins
Brakes - Vibrations While Braking
SI No. 510-1919
PI No.
Date June 1998
Distr. all
900
Vibrations while braking
Cars affected
All Saab 900 M94-
Background
If a customer experiences vibrations during braking, it can be due to two possible causes:
-
Excessive irregularity of the wheel hub.
-
Excessive thickness variations of the brake disc.
If the total run-out of the brake disc/hub exceeds 0.08 mm, both the brake disc and wheel hub must be replaced.
If only the brake disc is replaced when a significantly uneven wheel hub has been confirmed, front assembly vibrations will reappear after 650 - 1000
miles (1000-2000 kilometres) of driving.
If only thickness variations of the brake disc have been confirmed, that is, the wheel hub is not significantly uneven, replace only the brake disc.
It is important that both the hub and brake disc run- outs are measured in order to avoid the problem with reappearing vibrations.