Melted Rear Brake Pad Sensor - 986 Forum - The Community for Porsche Boxster & Cayman Owners

maj75 · 10-31-2011, 01:39 PM

I recently attended a DE at Homestead Speedway. It was my first DE and I had a blast.

Midway through the second session, the Brake Wear light came on. I thought it was odd as I had fairly new pads on the car, but I finished out the sessions with no issues. I ordered new pads and front sensors thinking that would be where the problem was. I finally got around to replacing the pads yesterday and to my surprise, the pads were all fine.

The problem was that the brake pad sensor on the passenger side had melted in the outer pad. The plastic housing on that side was deformed and the wire was exposed.

As I intend to do more of these events, I would like to prevent this issue in the future. Anyone have experience with this? Any ideas how I might prevent the problem? The pad and caliper are fine, the piston moves normally. Car is 2000 Boxster S.

The Radium King · 10-31-2011, 02:26 PM

do you need the sensor to tell you how much pad you have left? if not, then you can fool the car into thinking the sensor is there ... cut the wires and twist them together (the sensor works by sending a signal through them - all good the signal gets through - bad pad and the sensor gets abraded and no signal shall pass).

maj75 · 11-01-2011, 07:40 AM

I realize that I could fool the car/warning light by connecting the sensor wires, but I hate fudging thing. I am looking for suggestions as to whether the melting is to be expected and if there is any way to prevent it by using insulation or venting...

landrovered · 11-01-2011, 07:46 AM

I had a similar experience, I think the answer is to fool them for track days and then put them back to stock after the weekend.

thstone · 11-01-2011, 03:33 PM

Melting the brake wear sensors is completely normal at the track. I fried all four of mine one day this summer. There is no known way to avoid this - if you replace them and go to the track again, you have a good chance of melting them again. Ask me how I know.

In the end, I replaced them and then zip tied them up out of the way and use visual inspection to monitor the wear on the pads. Not as handy as having the wear sensors but cheaper than replacing them. I go to the track pretty often so taking them in/out was more of a hassle for me than visually inspecting the pads.

jaykay · 11-02-2011, 06:29 AM

Pardon my ignorance but how hard / time consuming is to pull them out and then put them back again? Where do you tie them up for the track

Basic questions I know but I like to know others do things ...

landrovered · 11-02-2011, 08:08 AM

Just a matter of pulling the wheels off, not much to it and if you have a set of dedicated track pads then it is a no brainer.

thstone · 11-02-2011, 04:52 PM

Pulling them out and putting back in to the pads is easy. Just jack up the car and remove the wheel to access the brake sensor wire.

Using a zip tie, I fold up the brake sensor wire a few times and then neatly attach the brake sensor wire to the hard brake line where they come out of the rubber grommet.

Brad Roberts · 11-02-2011, 05:53 PM

Remove the bulb/drill out the LED. Sounds harsh? but if you cant look through your wheels and check the brake pads while walking up to the car.... should you really be tracking it?

B

jaykay · 11-03-2011, 10:11 AM

True, good point you are never on without 50% left to start.

It's just nice to retain the stock functionality and features o f the car. When does the warning light come on...what percentage wear?

Brad Roberts · 11-03-2011, 11:28 AM

I hear ya

Light comes on at 5mm's

What I teach people? Don't let your competition pads go below 4mm. The thicker the pad, the less heat transfer to the calipers/pistons less chance of boiling the fluid!!

and no.. I don't sell brake pads for a living.. I just bleed brakes a lot on cars with very little pad left!!

B

ChrisZang · 11-09-2011, 06:25 PM

Quote:

Originally Posted by thstone

Pulling them out and putting back in to the pads is easy. Just jack up the car and remove the wheel to access the brake sensor wire.

Using a zip tie, I fold up the brake sensor wire a few times and then neatly attach the brake sensor wire to the hard brake line where they come out of the rubber grommet.

I have them permanently ZIP tied, I simply check manually from time to time.
Considering that they are plastic and the heat the calipers have to withstand they simply MUST melt.
You can usually tell people who track their Porsches by the discolored calipers (mine are somewhere between red and brown)