TMH

In the '87 Carrera while driving home Sunday night the brake system warning light came on. No audible warning at all. Checked the brakes and everything seemed fine, so continued home. Shut the car off and re-started it - the brake system warning light did not come back on. Checked the MC fluid level and it was fine. Brake system flush and fluid change about 8 months ago, and the warning light had never come on before. Also had the brakes checked at during the last oil change, about a month ago, and they were fine with more than half of the pad remaining.

Driving to work Monday morning, system light came back on. Once again, no audible tone or "chirping" which I read about when I did a search of this BBS. Driving around Monday afternoon and to work again Tuesday morning, no warning light.

Any thoughts on what might be causing this (so far) intermittant warning light?

Thanks,
Tom

Bill Gregory

Typically, the warning light comes on based on inputs from one of two switches on the master cylinder. Assuming there's not a short somewhere, you may need to replace them in the near future. They run around $25 each, although you can buy third party and VW switches for less.

Hugh R

Check the brake pad sensors, I believe that they work by touching ground (the disk) and turn the light on. When you shut the ignition off, they reset. You might have a bare wire on the sensor touching something, or one pad is truly worn down.

rbcsaver

I agree with Hugh R's assessment. Probably a bad wire /short as designed when the pad wears down. FWIW, I have mine disconnected and tied up with
nylon ties after using non-sensor Pagid Orange Pads for the last 8 years and I keep an eye on wear.
Regards,
Steve

TMH

Thanks for the help, guys. As of today the master brake warning light has not come back on after the 2 times it lit earlier this week. I'll check all 4 brakes this weekend, including verifying that the sensor wires are all making good contact at their plug-in connections.

I don't see anything wrong at the MC, but if a switch is going as Bill suggests, then I am sure that this little red light will be back on sometime soon.

Thanks again,
Tom