OPEL KADETT D SQUEAKY BRAKES
Q
I have a mysterious problem with my 1979 Opel Kadett D. On several occasions during various visits to my local garage, I have asked them to locate an annoying squeal from what I believe is the rear brake drums. The squeal is apparent during braking in the initial stages of each and every journey, and will eventually disappear after driving for around two to five miles with normal brake use during the journey.
The drums have been cleaned and checked, as have the brake retaining springs and brake shoe position. I am certain that the noise is not from the front, and the front brakes have also been checked anyway and confirmed to be in a good condition. Could the problem be with the brake back plates? I am now getting paranoid about this squeal and dread taking my Opel out.
AIf the duration of the squealing noise is extremely short and only occurs as you press the brake pedal, then the noise may be due to the contact surface of the brake shoe rubbing against the back plate. This may be remedied by a coating of copper grease on the contact points.
However, from your description I feel that the noise may be more prolonged and is occurring from the contact between the brake shoe and drum. The only way the backplate would influence this noise would be if the backplate were bent or distorted, allowing the shoes to sit out of line. Heavy corrosion may have weakened the backplate, but I suspect this would have been picked up by your garage already.
My feeling is that the noise is being produced by the vibration of the brake lining material itself, and it must be considered that this may be quite old. In the first instance I would try putting a large chamfer on the leading edge of the brake shoes to allow the initial contact area to be larger and thus lessen the possibility of the vibration. If this does not have a positive effect, and providing the backplates are not excessively corroded, then I would consider replacing the brake shoes.