Need help fast - Caliper problem

[xveganxcowboyx]

I've been working on the most difficult brake job of my life. After solving several big problems I'm all ready to put everything back together and I run into one more.

The right rear caliper is stuck. I had someone depress the brake to check for leaks earlier so the piston pushed out to it's full extent. Now it refuses to go back in. I've tried slow gently pressure, wiggling, a c-clamp, etc... Nothing. It wiggles side to side a bit, spraying small amounts of fluid out the hose hole, but it refuses to depress at all! Is there something I haven't thought of trying or did this thing just pick a strange time and way to seize?

 

[fastalon82]

Okay, first, the brake piston rides on a square cut seal and that is all that brings the piston back, so it will only move a very, very small amount back and forth, now if youre trying to push it back with a clamp while it has fluid behind and the cap is on the resivior, youre gonna break something. If youre worried about it still, take the caliper off and put it in a vise and push it in, if it wont go it like that then its just seized up.

 

[oldman]

I've been working on the most difficult brake job of my life. After solving several big problems I'm all ready to put everything back together and I run into one more.

The right rear caliper is stuck. I had someone depress the brake to check for leaks earlier so the piston pushed out to it's full extent. Now it refuses to go back in. I've tried slow gently pressure, wiggling, a c-clamp, etc... Nothing. It wiggles side to side a bit, spraying small amounts of fluid out the hose hole, but it refuses to depress at all! Is there something I haven't thought of trying or did this thing just pick a strange time and way to seize?

The rear calipers needs to be turned in CW, it will not go straight back. Use a needle nose plier to turn and push at the same time.

 

[xveganxcowboyx]

The caliper is off. I was worried about pressure, but the bleeder valve was seized so I removed it entirely leaving the main hose connection open. Pressure should not be an issue.

I am attemting to use large c-clamp. Would it be a good idea to put even more pressure on it with a vise?

Could the edge of the piston have caught the internal wall?

What do you mean by square cut seal?

How far is it reasonable for the piston to extend? It is about 1 inch out from being flush, but the boot extends that distance no problem.

Sorry for so many questions, but I need to have this thing up and running tonight if at all possible.



*Edit* Just saw your post Oldman. Will try.

 

[xveganxcowboyx]

That did it. THANK YOU!

 

[oldman]

That did it. THANK YOU!

You're welcome.