[quote name='RPM' post='30039' date='Jan 19 2007, 07:40 PM']Who ever heard of such things? I thought I had all of the parts to do the rear brakes, new rotors, pads, and sensors. No such luck. Luckily my local shop has some on hand that I can pick up in the morning. Most online parts sources do not even list the darned things!
They are mentioned in Vol III of the factory manual - when all else fails, read the instructions.
Edit/Update: The PET only shows them on the front brakes. I found them on the rears. Anyone know if they are required or necessary in back?[/quote]
These things are in there to reduce brake noise, I found out the same way when I did the front brakes this summer. On the front calipers there are two different sizes and a couple of the on-line Porsche parts places listed both sizes, they aren't cheap, cost almost as much as the pads. I found several posts on them and it was obvious that the "track guys" don't use them as they defeat the quick change design of the calipers.
I just removed them, prying them off the pads while stillin the calipers, stripped off the old goo, wire brushed off the rust and corrosion, resprayed them with an anti-sqeal brake goo (ugly red color) and installed them. Using the anti-squeal junk definitely makes this a messy operation, but since I was replacing rotors as well I wanted to do as much renewal as I could. I was using different pads that are supposed to be dust-free and quiet so I can't say if I really needed the shims with the new pads.
It would have been much faster to either have new shims or skip them, but after I broke one of the sensors, I wasn't going to finish that Saturday anyway, so letting everything cure overnight didn't really delay things. BTW I used J-B Weld to patch the cracked sensor, filing in a new mounting flange into the J-B-Weld, and it's still holding.
-sp4149
