Caliper servicing

[jon grindall]

Good morning and a very happy new year to all.
I'm about to fit new front discs and pads to my pre facelift 996, and I want to service the calipers at the same time (I suspect the outer pistons are sticking/seized) Can anyone point me to an appropriate thread - I don't think Rodney's goes into this - or give me the benefit of their own experience. Is it a DIY or indy job?

Many thanks
Jon

 

[Richard_Hamilton]

Early 986 and 996's suffered from water ingress into the brake servo, which could be causing the brakes to stick. Porsche modified the seals in 1999, which virtually eliminates the problem.

If it isn't the servo, unfortunately Porsche don't do a replacement seal kit. The calipers are made by Brembo, so you could find a Brembo agent to refurbish the calipers or supply the seals. They are available - a quick search on RennTech gave me this reference (http://www.zeckhausen.com/Brembo/Consumables.htm) but I expect it would be easy enough to find a UK supplier.

You might want to get them painted at the same time......

HTH

 

[danofesher]

I've used the people that advertise in some Porsche mags (classicar automotive, see http://www.classiccar.net/cdps/cditem.cfm?NID=4395). They did my ATE calipers for my 3.2 and they put new pistons in (they get pitted) and pressure test. I don't know whether the aluminium Brembo calipers also use steel pistons, if they do they'll pit so you need new ones.

 

[jon grindall]

Thanks,both for helpful replies.
Having stripped both sides the pistons seem free and dry, but the old brakes were struggling even to be derusted by applying the brakes! Perhaps the servo is the problem, Richard,as you suggest.
I'll try the brakes again once the roads dry, and if new discs & pads haven't improved things, I'll see if Autostrasse can look at the servo. I presume any replacement would be the upgraded design.
Jon

PS I got them painted....

 

[Richard_Hamilton]

The servo is the same - it is the sealing rubber boot that was upgraded. Like I said, it's fairly common - the servo chamber fills with water and goes rusty inside. And I mean thick, brown, gungy rust - not a pretty sight.