Am I missing something? Calipers

[jgiroux67]

Just got these 911 Sc calipers. Am I missing some pieces from them? I am not familiar with these so I dont know. It looks as if there is no pistons or is that what it is supposed to look like.

[juanbenae]

the rusty part in the center is the piston, around that the rubber is the dust cap. those need a rebuild before putting them in service.

[jgiroux67]

another

[jgiroux67]

last one

[vash]

http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm

[unclebilly]

I'm rebuilding mine in my 77S right now. The frozen pistons area real ***** to remove. Any ideas beyound my vice grip on the smaller diameter part and trying to wiggle and giggle?

I got the backs done OK and am now fighting with the fronts.

BTW, there is nothing missing on those calipers except for the pins and clips that hold the pads in.

[dtw]

jrigoux: Yeap, they're all there. You've even got caps on the bleed nipples.

unclebilly: Use air to force 'em out. Do a search, there's lots of threads on brake overhauls.

[unclebilly]

I tried air. They're in there pretty good. I'm thinking about hooking them back up and stomping on the brake pedal...

[vash]

unclebilly, i used a bike pump. watch your fingers!

[KobaltBlau]

Originally posted by unclebilly
I tried air. They're in there pretty good. I'm thinking about hooking them back up and stomping on the brake pedal...

that is one of the surest ways. try it!

[Oldporsche]

I knew a guy that touted the use of a grease gun. He produced an adapter to either the bleed nipple or the brake line connection that had a grease zerk. I claimed that he could use his lever pump grease gun and it worked every time.


David Duffield

[golfnow]

Originally posted by old_porsche
I knew a guy that touted the use of a grease gun. He produced an adapter to either the bleed nipple or the brake line connection that had a grease zerk. I claimed that he could use his lever pump grease gun and it worked every time.


David Duffield

I’ve heard of this also and its supposed to work well
But I don’t know how you get the grease out when your done

[juanbenae]

thats what i was thinking golf. seems like you would have a bigger problem (read mess) with the grease. i would put some liquid wrench on them and fashion an adapter for your compressor. man when i did mine the puck nearly cut my finger off as it pinned it against the other side of the caliper as it flew out. it was like an f'ing rocket, made a cool pop sound.

[KobaltBlau]

yes, the air works well normally, but I think the issue is if the pistons are rusted to the bores, if they have been sitting for a long time unlubricated for example. This brings up the question of do you really want to reuse them if they are siezed/rusted.

[jgiroux67]

Is it even worth taking the pistons out? I mean if the seals are still good and all is there a reason to? For sure I am going to put new dust caps on but if there is slight rust on the pistons do they need to be fixed?

[golfnow]

I would take them out, clean them and see if
they are still good, the chances are good that they
have rust on the pistons and it would cause them to
stick, Mine did on an 86, I don’t think the brake fluid
was ever changed out before I got it. I just rubbed them with
some paper until they where rust free also the insides
of the calipers. You don’t what to use anything too
Abrasive

[unclebilly]

I got 'em out. Air at 150 psi and tapped gently on the stuck pistons with a punch and hammer. Slowly but surely they came afer liberal soaking with all sorts of chemicals. The pistons are rust free but there is a ton of crap in the bore outboard of the O-ring from shotty dust covers...

[jgiroux67]

Alright I got one piston out, but how do you get the other one out? Air just comes out of the open space where the piston used to be. What is the best way to block this section off?

[Jdub]

You guys are NOT USING THE SEARCH BUTTON!!!!!!!!!!!!!!!!!!!!!!

This is ALL discussed: how to get one out and then the other. Search under caliper and my screen name (Jdub).

You need to block the one caliper to keep it from coming totally out, then get movement on the other.

John

[mtelliott]

Listen to John.

This has all been documented. However, all you have to do is rebuild the side you got out, put it back in, put a clamp on the rebuilt one, and the air will get the other one out.

Penetrating oil on the piston left to soak overnight will help.