Avar928

This is for an early '86 928S.

I'm in the middle of refreshing my rears, new (used) rotors and new brake pads.

I got the brake pads from Roger (WBR Ceramics) but apparently they are VERY thick and won't even fit over the rotors once in the caliper. They won't even fit with one pad in on the outer most side of the caliper I'm not sure what to do apart from just re-installing the old pads.

Comparison of old and new pads.

GlenL

Squeeze the piston back with a big "C" clamp. It'll fit. With new rotors and new pads it's a really tight fit.

Avar928

Check the fourth picture with just one pad in, the rotor won't track into the caliper. I've already pushed the piston back as far as it'll go. There's probably 1/4in of space still occupying.

I'm thinking of installing one old pad on that outer most side and then a new bad against the piston. I tried it on the spare new rotor and it'll be tight indeed but at least she'll track in the caliper.

Edit:

Wait, I think I got it. The mounting frame was off and took up the space required. Moved it back and line it up the rest of the caliper.

Mrmerlin

take a file and clean the seating edges of the caliper and the pads so they slide into the caliper housing,

put the outer pad in first and make sure its seated into the caliper frame tab on the back of the pad,

then pry the frame towards the piston this should move the frame enough to fit the other pad.

also put the C clamp on the piston and caliper and make sure its fully seated ,
NOTE you may have to open the bleeder to make make sure the piston isnt being held hydraulically

Avar928

Gotcha Merlin. I'll try that. I managed to re-align the floating frame. It just has me worried it'll move when I re-install back on the rotor.

Mrmerlin

you have whats called a floating frame caliper,
its OK for one side to move out of square ,
simply pry it back to straight

928Myles

When you push the piston back it might pay to remove a bit of brake fluid from your reserviour so it doesn't overflow with the fluid that is pushed back into it.

Myles

davek9

You may also want to clean up those calipers, lots of old crud build up and that may be causing the two halves and the new pads to move freely.
The pads should drop right in and not bind, the two halves should also move unencumbered.

curtisr

+1

Is it also normal that the caliper appears to rub against the new rotor as well?

Avar928

Thanks everyone for the advice.

Managed to get the driver rear done. Working on the passenger rear now. I took the caliper off the car, disconnecting the brake line to work easier. I'll be power bleeding the brakes when done.