930 caliper piston seals

[mnez]

I am going to convert my 3.2 to the 930 brake setup for track use. The calipers are used so it seems prudent to replace the piston seals. I have done 3.2 calipers and others, but never 930.

What are the 'scaper rings' and do they need to be replaced with the seals?

Is there an aftermarket source for these parts, or is it a Porsche part only. My local FLAPS supplied 3.2 seal kits, but have no listing for 930 calipers.

What do you 930 brake guys do?

Thanks.
Mike

[Steve@Rennsport]

Hi Mike,

930 calipers contain a seal and scraper for each piston.

The seals maintain the integrity of the hydraulics and the scrapers keep dirt, brake dust, and schmutz (technical term) away from the seals so they last longer.

These are factory items and you can get them here or the dealer, only.

[mnez]

Thanks Steve. So the scrapers function like the 3.2 rubber dust boots, but don't disintegrate?

[Steve@Rennsport]

Originally Posted by mnez

Thanks Steve. So the scrapers function like the 3.2 rubber dust boots, but don't disintegrate?

Yessir, thats basically correct,..

For the record, excessive heat will deteriorate the scrapers & seals so its imperative to use good brake cooling when the car is at the track.

Certain high-friction pads such as Hawks introduce excessive heat which mandates a proper brake cooling kit, too.

[mnez]

Good to know. With the Carrera brakes I have been using PF97 which I'm happy with, and those brake cooling scoops slung under the A-arms and ducted to the eye of the rotors. Intend to make the same work with the 930 set-up.
Mike

[Steve@Rennsport]

You will either need the larger 930 backing plates for your cooling system, or modify yours to prevent air from leaking around the edge of the plates.

[mnez]

Thanks Steve, I'll put those on my list. Hopefully I can get them separately on their own.
I've read that I need to remove the proportioning valve/restrictor from the rear brake line. Did the 930 have a similar valve, or is it just re-connected straight through?

Mike

[KTL]

I certainly defer to Steve's experience on the 930 brakes & seals. My experience has been, mostly on some older 951 Brembos with the same type of dust seal, is that they are quite durable with respect to heat. MUCH better than the Ate rubber seals that turn to ash. That said, i'm not saying cooling ducts aren't in order. Just saying that the nice thing about the scraper seals, despite their expensive-ness, is that they're pretty darn durable and that's a nice upgrade in & of itself.

You'll have to do some hunting for individual scrapers. Unfortunately Pelican only sells them as a kit per caliper and you are given a 4 scrapers, 4 pressure seals and 4 new pistons.

Yep you remove the pressure reduction valve from the rear circuit. You can simply un-bend the lines and use the existing union to re-join them. No need to make your own line.