Threw on a new set of rotors on my 85 GT. When I get to the calipers I can't get the caliper piston to push back. If anything its pushed out more. Any secrets to moving a stubborn piston or do I need new calipers. They are the original calipers, but with only 67,000 miles.
there is a special tool for it if you can pry it, i have it, it looks like two brake pads, and a bolt tht goes through it. You tightin it until the two brake pad look alikes are close together to fit into your caliper, and when you get it inthere, you spread it by turning the bolt, and it slowly spreads it and spreads it, until you have spreaded it far enough to get it around the rotor- good luck and dont forget to pump the brakes lol
Paul Perreca
This may be the complete wrong way to do it, but this is how I have always done it. While the old brake pad is still on there I just use a big c clamp on it to push the piston in. Taking the cap off of the resevoir also seems to help , but you may have to top the fluid off afterwards.
I always just open the MC cap, then use a small prybar or large screwdriver and pry between the pad and rotor to get it back, if I can't get somethign in there I use big vice grips. If they are frozen, just get new calipers because even if you do manage to get them back, they won't be right.
I like to pop the bleeder, so I am not pushing old brake fluid back up the lines (not to mention that if you topped the MC up since the last pad replacement, it will likely overflow).
I have done it like James does and that works (best to put a piece of wood behind the caliper to protect it, like I am sure he does). And now I use the tool Paul mentioned, which works very nice. They are like 5 bucks, so why not get one.
Jason is so spot on - if the caliper is that hung up, I would not want to reuse it. It will likely drag, bind and eventually seize (after a hard stop).
On old calipers, I have removed the dust boot and cleaned out the end of the bore (lost of brake dust gets in there). Rebuilding calipers is no biggie, but with as cheap as reman'd units are, there is no point IMHO (on bikes, I rebuild since reman'd ones are not a real option).
Whatever you do, do it right. Otherwise it will be unsafe and end up causing issues down the line (warping your new rotors, etc and cost you more money).
Good luck.
Took the MC cap off and pulled out fluid so it wouldn't splash over.
I have the tool that pushes the piston back, no luck.
Used the block of wood and c-clamp, no dice.
Tried a large screw driver with the old pads in, nope.
I exhausted every trick I knew of, thats when I get on the board and ask questions. Sounds like I need new calipers.
You probably did, but just in case, you tried to push them back in with the bleeder valve open? I have had to actually take the caliper off before and then use the tool to get it back in...but if that doesn't work...DECLARE SHENANIGAN!