View Full Version : Spongy brakes on start up

10-01-2008, 01:32 PM
When I start my 1996 A6 ( Auto) I find the brake pedal often feels wooden for the initial few seconds, and the brakes dont seem to bite the discs, This invariably occurs while reversing off the drive way and requires a good deal of force on the pedal to stop the car, however as soon as I select drive, the pedal moves down an extra half inch, the brakes then bite properly and everything feels normal. This does not seem to be effected by letting the car run for a few minutes as it seems to consistently require drive to be selected before the brake system begins to function properly, and likewise selecting reverse doesnt seem to do the trick, it only seems to be selecting drive that brings the brake sytem into normal operation. Has anyone experienced similar, or does anyone know the cuase??

Peter D
10-01-2008, 05:29 PM
Two possibilities come to mind. 1/. this is an auto and you may have a secondary air pump ( electrical which cuts in when the throttle is off if this or it's sensor has failed you may not have enough assistance then at idle or in reverse if you are not using any throttle. Do you have a vacuum servo or have you got the hydraulic pressure reservoir older version and is it not holding it's charge. Regards Peter