Rear Brakes on BMWs

Hey everybody. I am having a lot of trouble reassembling the rear brakes on my sister's 1997 318i. (The same exact thing happened with my Z3). My problem is getting the OEM BMW pads to fit back into the caliper. I can get the old ones on and off with no problem, but they're 6 mm thick - the new ones are FAT.

Is there some sort of weird procedure to this? With the Z3, I seriously cheated and put two old pads back in temporarily until the new ones wear a bit.

I pushed the piston in all the way (like I would with any other car), I am not putting them on upside-down, and I tried putting the piston side in first as well as last. I am stumped. Any ideas?

I may have gotten the wrong ones, now that I think of it. In 1997, there was a change and I couldn't get the VIN number to check them, so the BMW guy just gave me the ones I have by chance. Crap. But with my Z3, I had the VIN when I ordered them, so I'm almost certain that I have the right pads for that and yet I had the same problem - the pads are too thick.

I remember hearing that some BMW's of that era need a special tool to retract the piston and/or install the pads. A Mazda mechanic I know ran into this when he was trying to change rear pars on 535.

I don't remember anything special about this. I also checked a couple of manuals, including Bentley, Haynes and Dempsey's 3 Series Performance Projects - no mention of either a special tool or unusual procedure.

The special tool is a 7mm allen key to retract the brakes if you have an older model. This one is pretty standard - push piston in, install pads. It just has huge pads that don't fit.

Sounds like you ended up with the wrong pads or the piston isn't returning fully into the bore. The piston should end up flush with the caliper housing, anything less and you have debris/rust in the bore.

ansonivan wrote: Sounds like you ended up with the wrong pads or the piston isn't returning fully into the bore. The piston should end up flush with the caliper housing, anything less and you have debris/rust in the bore.

I'll have to look into this. I got the fronts together easily on my Z3. No problems at all. But both rears on that car (done a few months ago) and, so far, the only rear caliper that I've taken a shot at on the 318 have been the same. I mean, It's not even close!

Actually, you know, the slider bracket is fully compressed as well and the piston-side pad is resting firmly against it. Really, the clearance is way off. It's not even close. Something else must be wrong. Maybe I'll snap some pictures when I get home.

Argh. I drove to BMW to get the "right" pads after the part number they read to me didn't match the one on the box. Turns out, I just read the wrong friggin number. Of course it didn't match! D'oh!

I still can't get the mother truckers to fit. It's like they are 1 mm too thick. Pad material contacts other pad material before I can get the outside pad onto the bracket. I'll see what the bimmerforums.com people said.

Fixed it. I just needed to take the slider pins out (didn't know mine came out). Had to buy a 7mm hex to get it off, but it was worth it. EASY AS PIE!

Thanks everybody!