One of my front calipers is not retracting properly so I'm considering buying a rebuild kit. These kits don't seem to be available outside the porsche channels, design 911 doesn't seem to sell them either (only up to 89) just like other discounters in Germany.Should the spring plates be replaced aswell? While I'm in there is it worth replacing the brake lines with ss? Would this be good preventive maintenance?
Tx

 

Ive been told that to replace the spring plates is a b*tch of a job,as the calipers have to be split in half and the screws that holds them in is usually coroded to hell and needs drilling out.A porsche mech friend said you are better removing the calipers and getting them sent away for a professional refurb.
Just a pre warning

 

Try Pelican Parts...

 

Before you order anything I would spend two minutes going over the caliper. Corrosion buildup behind the spring plates could be the sole reason for the pad not retracting. If you remove a pad and operate the brake pedal (just a tiny, tiny bit) you can tell immediately if your problem is related to the pistons/lines or the plates. Most mechanics (mistakenly) just file away the edges of the pads so that they won't bind on the plates instead of doing the job properly and replacing the plates. You don't necessarily have to drill out the retaining bolt, just apply enough heat to release the loctite threadlocker. When rebuilding my front calipers the crap buildup behind the spring plates was so bad that I couldn't replace the seals without first removing the plates. If you decide to rebuild the caliper be aware that the reason the Porsche sourced rebuild kits cost so much is that they include two pistons. In the USA the seals & boots are available separately for less than $4USD.

 

Tx, the kit for the two front rotors is about 220 usd, with pistons. Two inner pistons on one caliper are damaged after I applied too much force to place the new pad. When braking I also feel some kind of pulses through the pedal. Tx for the tip on the retaining bolt for the springplates, I'll try that first.

 

Hi Jason,

i am interested to get the seals and boots. can you please advise ?

thanks
James

 

Unfortunately the last time I checked the website for True Choice they no longer had the boots or seals listed (previously they were $3.75USD/each) but I haven't tried calling them recently (1-800-388-8783). If they don't carry them an alternative source is StopTech, they sell the boots and seals for $50USD/ per caliper (a little more expensive but still cheaper than buying from Porsche). Also take a look at your caliper spring plates and make sure they are not pushing away from the caliper. If so, they can be replaced for $13USD/each. As long as you use heat and a T27 Torx head-driver you shouldn't have any problems removing them. People start having problems when they don't use heat on the bolt and they mistakenly try a hex-driver (allen key) which completely mangles the bolt.

 

Hi Jason,

Thank you for the information.

Cheers
James

 

James have you managed ot find a source for the seals yet? if not looks like stoptech is the only option. I have emailed true choice but not had a reply yet.

on the stoptech site they list all different sizes of piston anyone knwo what size pistons we have?

 

Pesty have you tried an OPC? IIRC they quoted me £30/piston and £14 per caplier plate as replacements when I was looking, they wouldn't sell the small bolts for the plates seperately to me at least, kit form they said.

Kevin

 

Hi,

so far no news from stop tech yet.

Tried Zeckhausen racing, they do not have the 32mm seal...

so still in search for the complete set of seals...

cheers

 

Kevin thats a pity about the bolts I was hoping that I coul re-use my plates after cleaning all the crap out behind them.
It also explains why someone appears to have replaced the torx head screws with ordinary pan head hex screws which have all but rotten away.

the only other place Ive found selling kits is FVD but that includes the pistons which I dont need.

So our pistons are 32mm then? are all seals and dust caps the same? could we use any rebuild kit for a 32mm piston?

 

looking at pelican parts apparantly we have 2 x 40mm and 2 x 36mm pistons percaliper. they sell seals but are expensive.

http://www.pelicanparts.com/catalog/...pg3.htm#item15

Caliper Piston Diameter - Air-Cooled Models
Model Front
Piston 1 Front
Piston 2 Rear
Piston 1 Rear
Piston 2
964 C2 ('92-on)/C4/RS America 40mm 36mm 30mm 28mm

 

I've just purchased a set of seals from StopTech for the front calipers on a C4

89-100-3640 Seals & Dust Boots - StopTech ST-40, 36mm 40mm 1 $50.00

I spoke with them on the phone and they confirmed the sizes. I haven't installed them yet.

Cheers,
Dave

 

Pesty, I should be able to get hold of some button head bolts, If you need them, I just cleaned up my plates and used the stainless steel buttonheads I found as replacements.

Kevin