transporter2004

Hi All,
Got in my 2004 A8L 78k today and the parking brake switch and the warning indicator kept flashing along with the "brake" warning. The brakes work fine and so does the parking brake. I tried the parking brake while rolling and the brakes locked the rear wheels and released. While driving they flash and a loud tone comes out of the dash. When I stop the car, they stop.
Please advise

Thanks,
George

Keep the shiny side up!

MP4.2+6.0

early ones are known to often have a faulty brake pedal light sensor, making system think brakes are applied. Considered a relatively minor fix.

Mike_k

Bet you $10 only one side of the parking brake is engaging. My car did the same thing. The motor on the right side went dead. The only solution to make the car temporarily driveable was to remove the two 30 amp fuses in the trunk fuse box (2 bottom, green 30 amps). Otherwise the thing beeps at you straight for five minutes.

The more common problem is that the wires going to the parking brake motor get corroded or fray. You might check that as well.

A bad brake switch light shouldn't trip the actual brake light. I believe it just trips the traction control light for each instance it occurs.

transporter2004

You guys are great!!!! I do appreciate it and look forward to many more years of driving my A8L. By far the best car on the road.

williebone

Agreed! It is very annoying and I couldn't take it, so I ran though a few simple steps. We tested the Parking Brakes while one of us was at each Rear Wheel and what I thought was a Working Parking Brake turned out to be just Noise from the oposite side bouncing off my Garage Walls. We then tested each Parking Brake Plug and found out that there was Current to each Plug. Long story short is that the Left Side (Driver's Side) Parking Brake Motor was Shot. We noticed that it was Beat Up from Driving over the Years and is Exposed to the road. The housing is Aluminum and is easily Damaged. Replaced with New Parking Brake Motor and all was quiet again. Warning! You Need VCDS to do the Job. Good luck and laters,

deadcandance

Hi There Williebone.... do you mind if I ask how much the parking brake motor was? Where you got it and is it an easy job to change for a novice DIY?

transporter2004

OK I have my car at the indy this week and he is going to attempt to replace the rear rotors and pads without repairing the parking brake. I really do not want to purchase a rear caliper in order to do the rear brake job. He seems to think he can take the caliper off the car and back the parking brake out in order to to the brake job.
I will let you know how it goes.

mishar

It is possible even if parking brake is not working. Just screw the piston in to accommodate new pads.

By the way, you may check parking brake harness while you are there.

MP4.2+6.0

is actually a thin layer of sound insulation I think, with an aluminum foil outer face. Gets inevitably nicked up just removing caliper for brake work. Not sure how robust the motor assembly is under it, but I remember one post where someone used the old C-clamp method and promptly crushed it.

mishar

Piston can't be pushed back in using C-clamp.