This may be a dumb question, but I have never done rear brakes on an FD before... I have read on Brian Dowling's site that to retract the rear brake pistons you need to screw them in clockwise. He never says though if you need to screw the pistons back out after installing the new pads.

Do I need to do that or is the point of screwing them in is so they fit over the pads?

I want to put them in tomorrow, so any help would be appreciated.

 

The pistons rotate taking up the slack as the pads wear. So ur retracting the pistons to make room for the new thicker pads. And no you dont have to do anythng once they are retracted and pads put on.....once everythng bolted back up pumping the brakes a few times will seat them along w/ following a proper break-in.

 

Thank you. That is what I thought.

 

While you guys are on the subject. I was wondering, my '85 Fiero had a mechanism that racheted out the rear pads as needed when the emergency brake was pulled. Is that how they work on the RX-7 ? Tom

 

Actually, the pistons don't rotate while in operation. They only push out. When the brake pedal is pressed, the pressure pushes the caliper straight out. The shaft is used when the emergency brake is pulled. It applies pressure to the caliper piston. Again, only straight out. As the brake pad wears, there is a one way bearing and shaft assembly that the emergency brake uses. This is what rotates as the pad wears. It allows the piston to extend inward without losing the emergency brake adjustment. When new pads need installed, rotating the piston one way will allow the one-way bearing to grip and spin the screw assembly back towards the caliper. Spinning it the other way should only allow the piston to spin.

Be careful not to tear the dust boot when screwing the piston back in. Use some silicone spray on the boot and break the "seal" of the rubber against the piston. This will allow the piston to spin freely. If there is brake fluid behind the dust boot, you have a bad piston seal and the caliper needs rebuilt. I have rebuilt them, but it is best left up to professionals.

Once the new pads are in, the brake self adjusts with use. Just pull on the emergency brake a few times until it tightens up or pump the brake pedal a few times to seat the pistons properly.

Good Luck,
Tim McCreary

 

Thanks Tim, Sounds just like the Fiero. I remember having to be careful of the rubber boots. Tom