So I've has this lovely squeak that progressively got so bad that I don't even drive the car at this point. The squeak is coming from the rear drivers side wheel, initially I thought wheel bearing, but now I'm confident it's the brake(s)?

It used to only squeak when I hit the brakes, but now it's constant even while I am cruising (gets worse when I hit the brakes).

First thoughts now would be seized caliper, worn brake pad(?) worn pads usually make metal on metal grinding sound I thought, not such a horrible squeak..

Anyways, I haven't had any time to get it off the ground to take the wheel off and take a look at it, but I was able to snap a few pictures and I was a little surprised at what I saw.

Seems there's no visible brake pad on the wheel that's squeaking, am I wrong? Here's a picture of the brake in question.



Now here's a picture of the other side (rear passenger)



Seems like I see a pad in the second picture, yet I see absolutely no pad in the first picture, I'm not a brake expert, so please don't flame.

Thanks for any and all help

 

Time for a brake job. And take a good look at the slide pins on that side where there's no pad left. Usually uneven wear is because one of the calipers can't move away from the disk when you let up.

 

^ Yup. It looks like the slide pins on the driver's caliper are stuck and so it wore through the outside pad faster. You'll want to disassemble and see if the pins are salvageable. At the very least, you'll need a new set of rear pads.

 

Is that a "seized" caliper? If the slide pins are stuck?

Where can I buy new slide pins if they are stuck and aren't salvageable? What about good parts source for pads/rotors/etc?

Thanks for the replies guys, might end up just taking this into a shop and have them deal with it, unless the brake job isn't too time consuming, I just never have time to deal with **** like this, also, is the special tool for the rear brakes required? Any special tools needed for the fronts?

 

Usually a "seized" caliper refers to one where the piston in the caliper won't extend/retract. Since the outer pad on that side is worn, the caliper is obviously putting pressure on the pad. It is rather the mounting hardware for the caliper that may or may not need to be replaced.

From my cursory search, it doesn't appear that the pins are sold separately for the rear as they are the front. You can get the whole caliper carrier from ECS for a little over $50. You may be able to score one from a partout here or on Vortex for less.

Audi B5 A4 Quattro V6 30v > Braking > Caliper > ES#3512 Rear Caliper Carrier - Priced Each - 443615425B

Yes, there is a special tool for retracting the pistons on the calipers. You can buy one or rent one from most parts stores.

If I were you, I would buy a set of pads for the rear. Remove the caliper and carrier on the offending side. Take out the pins from the carrier and grease the bejeezus out of them and install the new pads. Do the same for the other side. Shouldn't take more than an hour. Worst case is you need to find a new/used carrier.

Drive for a while and then reinspect that side again to see if it has gotten hung up. Otherwise, you're good to go.

 

I bought an A6 a couple years ago that had been in a backyard for 2 years and hadn't moved. Slide pins were rusted solid on one corner. I took the caliper carrier out and soaked it all in PB Blaster, then put it in the vice and started working it. I got it out, and once you get it out, you can usually just sand it down with emery cloth. I don't think you'll have to buy new pins.

But as bshusted said, "grease the bejeezus out of them".

 

If you grease them to much you could cause the sliding pin not to slide in all the way because to much grease would be built up at the end and around causing the caliper not to fully compress.