another brake caliper rebuild question

hot66 · Post by **hot66** » Mon Mar 15, 2004 10:34 pm

anyone got any suggestions on how to get both my pistons out of the rear callipers?

Both are really sticking, but using air pressure I can get one to pop out (explode out more like

), while the other is almost all the way out. Prob is even tho the remaining piston is almost out, I can not fully remove it. Anyone got any tips?

I was thinking of replacing the seals etc for one piston, pushing it back in & then popping the other out etc.

Also, can anyone recommend some good rebuilding 'grease' to use with the rebuild kits?

Nick Moss · Post by **Nick Moss** » Tue Mar 16, 2004 9:19 am

The kit should come with grease. I think it's silcone grease

Berny · Post by **Berny** » Tue Mar 16, 2004 12:03 pm

I use a master cyl and pipe to force out the pistons, use a G clamp to hold one in push out a little clean use wd 40 and push back make shure you keep it stright do this a few times till it moves well, Keep fingers out of the way I have seen people jam them ! I use red rubber gresse.

Post by **Miggs** » Tue Mar 16, 2004 5:44 pm

yep agree with berny on that done mine red rubber grease and g-clamp while you blow the other one out it is easy once you sussed out how to do it

hot66 · Post by **hot66** » Wed Mar 17, 2004 8:48 am

Miggs wrote:yep agree with berny on that done mine red rubber grease and g-clamp while you blow the other one out it is easy once you sussed out how to do it

thats what I've been doing. I have one of the pistons almost out, clamp it & then blow the other one out. Prob is I can't then remove the one that is still in the calliper, even tho it is almost all the way out. These pistons are really tight, I have to use a clamp to reinstall them (with the old seals, have yet to try the fit with the new seals)

Where do you get the red rubber grease? motor factors?

Berny · Post by **Berny** » Wed Mar 17, 2004 10:17 am

Are you cleaning and then useing wd40 on the piston before you push it back, sometimes takes time you have to push it in and out several times, where have I heard that before, yes try motor factors for gresse.

Post by **Miggs** » Wed Mar 17, 2004 1:10 pm

have you tried some pump pliers?? when i got mine out i cleaned them with some 400wet and dry then chucked in rubber grease any where that sells car stuff will sell the grease

hot66 · Post by **hot66** » Thu Mar 18, 2004 10:29 pm

right getting somewhere now.

Removed one piston. Piston & bores are smooth & clean. The area on the 'outside' of the seal was very cruddy & rusty thus preventing the piston coming out freely. Smoothed this area using 800 wet & dry & the piston now moved into the caliper up to the 'rod' OK. Fitted new seals, lubed & pushed piston back in.

Repeated for other piston.

My problem now is the pistons still seam to be reluctant to go all the way into the caliper. I have to use a g-clamp to get them to slide down the 'rod'. When I tested the caliper it took about 8bar to get the pistons to actually move out. This doesn't seem right to me.

Anyone got any suggestions on where the problem might lie?