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Rear Caliper Rebuild Serious Problem!

Posted: Fri May 06, 2005 1:11 pm
by Greg Gordon
My Personal 1985 GTV6 sat for a full 12 months while it served as a jig to make the supercharger kit. As we all know that's really bad for all the hydraulics. Since I put it back on the road, every couple months something hydraulic seems to fail. Up until now that's not been a big deal since I fully expected it. Not a problem that is until a rear caliper started leaking.

Now I have a real problem. I am wondering if anyone else has had this one. The right rear caliper is leaking from the internal seal at the handbrake actuator. That's a BIG problem for two reasons. The rebuild kits sold by the usual vendors SUCK. They only have the rubber ring that seals the piston and the dust cover. They lack everything else. For example they don't have the rings that seal the two halfs of the caliper. Now I know the official line is don't separate the halfs but it's not really possible to clean it properly if you don't. Plus it seems to me that it's common sense to replace 20 year old rubber seals in the braking system while you have it apart.

Anyway...Does anyone know:

1. Is it possible to get to and replace the seal for the handbrake actuator on the brake caliper? It looks like it might be possible.

2. Where can I get that seal? For that matter, where can I get the seals for the two halfs, new bleeders, and the plastic nut style dust cover for the outboard adjuster. All stuff that should be in the rebuild kit.

3. Oh, and another thing. It looks to me like ATE used some sort of sticky non hardening goo to insure the inboard adjuster doesn't back off once it's set. Without this goo or something similar there is no way the handbrake could be expected to work for more then about 500 miles.

4. If it's not possible to fix a leak at the handbrake actuator then that means these calipers have a built in life limit of about 25 years so we will need to find a substitute. Does anybody have a caliper replacement that's inboard and has a working parking brake?

Thanks in advance,
Greg

Posted: Fri May 06, 2005 2:44 pm
by Zamani
Greg,

The places which sells the SZ caliper spacer upgrades (i.e performatek.com) should have the seals when you seperate the halves.

P/S why not just buy a rebuilt caliper. Your worrying is probably worth more than the rebuilt caliper. :D

Brakes

Posted: Fri May 06, 2005 9:17 pm
by MD
Greg

One of the key problems in the hand brake area of the caliper is corrosion. The reason why they leak is often due to this. In any rebuild you undertake, my advice is that you get the callipers resleaved with a stainless insert here.

It's what I did on all of mine. Not cheap but no come backs either.

Posted: Sat May 07, 2005 5:11 am
by tectoteam
i like to do all myself...

but in this case...yu will waspe so much money and time to find seals......however not sure that works if its corroded at this aera.......

imho buy a rebuild caliper from performatak or iap...its not so expensive.....!

Posted: Sat May 07, 2005 6:18 am
by Greg Gordon
Do the rebuilt calipers have new seals between the halfs? Do they rebuild the handbrake area that's the problem on my caliper? If not then the life of the rebuilt caliper may not be quite what I am looking for.

I am all for buying a rebuild caliper if "rebuilt" means they replace all the rubber and possible wear items. If it just means they cleaned it and replaced the seals in the "rebuild" kits out there then that's just not OK with me.

Posted: Sat May 07, 2005 6:53 am
by tectoteam
re.

they dont rebuild yur ones.

every seal is new..... and each parts that can suffer from anything is new to.....

in fact.....its close to be a new caliper in axchange of a little money and a old caliper.

look at this:
Image

its for yu for just 107 $ !!!!!!!

Posted: Sat May 07, 2005 10:14 am
by Barry
If thats not a brand new caliper,these guys selling these are bl**dy good at rebiulding them...They need some freebie mention here ,me thinks...

Greg,In the year dot when I still rebuilt the rear caliper I used to machine up teflon seals for the calipers..Never had any problems...Im talking handbrake mech. here...

Posted: Sat May 07, 2005 4:00 pm
by Greg Gordon
Do the rebuilt calipers include seals between the halfs and for the handbrake mechanism? If so I will get them. The one in the picture looks good but that's just a matter of cleaning it really well. I am interested in function here.

Posted: Sat May 07, 2005 4:23 pm
by 4SFED4
Greg,

The spacers available in the US are made by Jim Steck. I forget who is retailing them as a kit... you could ping him to find out. He just made another batch last week I think. I believe everything you need is in the kit. The prototypes are still on my car... 25K later and no problems to date.

Posted: Sat May 07, 2005 9:38 pm
by Zamani
Greg,

Best if you you call up Andy Kress at performatek.com. I have one of their calipers. No problems so far.

Posted: Sun May 08, 2005 5:10 am
by Greg Gordon
Thanks everyone. I have decided this caliper failure is a sign from God I need to get around to pulling the transaxle and doing it's long overdue overhaul. While I have it out I will replace both rear calipers with rebuilt units, new disks and make a couple other improvements. This will delay installation of the new super hot 2.5 (275hp I hope...) I built and have sitting on my garage floor, but I have been putting this transaxle project off for a couple years so I guess I should get it done. I just plan to pull it out and put it back in, my dad will overhaul it for me so I won't loose much time on other projects.

Rebuilding Rear Calipers

Posted: Sun May 08, 2005 4:19 pm
by shures
The correct rebuild for this application is a stainless steel piston not a stainless steel sleeve. The piston seal is carried in the cylinder bore and the part that bears against it is the one that must stay intact to prevent seal failure. Andy Kress @ perfomatech carries rebuilds that should work although I haven't purchased them from him, yet.

Posted: Sun May 08, 2005 7:12 pm
by Greg Gordon
I am calling Andy!

Brakes

Posted: Mon May 09, 2005 3:36 am
by MD
Scott,

Just for the record I need to clarify my previous suggestion. When I said the fix was to stainless sleeve, I was referring to the hand brake section specifically within the caliper.

I can see now you could have interpreted my comment as applying to the main piston and cylinder section which it does not. Unless you do this, the problem will return over time but you should expect at least 5-10 years service out of standard changeover unit in any case-particularly if you change the fluid every 12-18 months.

Sorry if it caused any confusion.

Posted: Mon May 09, 2005 4:29 am
by Greg Gordon
I got it, thanks.