Tony

non issue with the propper brake tool..or as stated a C clamp. When ever i change my pads i run my pistons out to clean them

Darien

Well, now I did it. One of the pistons came out and some type of fluid came with it I don't have a seal kit, can I re-install the piston with the old seals??? What type of fluid came out, how do I service it?? This is un-chartered territory for me so any advice is greatly appreciated Did I mention that this is my daily driver

Bill Ball

Those pistons look like they need cleaning. Push the out ones back in and reinstall the pad on that side and then pump again to get the other side to come out some for cleaning.

Seals get brittle with age, so ideally they could be replaced. I guess no one has located the caliper repair kit for later models. I could not find the receipt for the kit I bought. I will go through my parts, as I recall they were in factory bags, and see if I can at least get the PN for the seals.

Bill Ball

Get a can of ATE blue.

Position the piston back over the bore and work it back in. It will go in. Sure you should get new seals, but short of that, put it back together and bleed the brakes.

Bill Ball

I can't find the parts bags. One of our sponsor vendors should help us out here. I can't find the seals listed anywhere yet. I'll keep poking.

Darien

Thanks Bill, looks like I'm not the only one up at the wee hours I cleaned the pistons best I could and put the 2 that fell out back in and bled the hell out of it. Man some milky fluid came out, no telling when it was bled last No leaks from the calipers, so good to go for now. I'll ops check it after I get some sleep

Bill Ball

Milky? You really need to flush. Get the ATE Super Blue. It makes bleeding easy due to the color change. Best to get a Power Bleeder or Mitivac, but short of that, open up the one of the rear, right bleeders and put a clear hose on it into a jar. Pump the brakes until the reservoir is almost dry. Fill it with blue. Pump until dark blue comes out the bleeder, periodically topping off the reservoir. Do the other calipers. You will use a bit more than half of a liter can, certainly less than a liter. Next time you do this, use ATE Gold. This is an easy job with most of the time spent getting the wheels off. Fortunately Porsche used bleeder valves you remove with a 10mm wrench or socket, so they rarely are hard to remove.

Mrmerlin

Hi I would be careful about using any solvents on the pistons , once they get wet with solvent it will wick into the seal grooves and then possibly damage the piston seals, the only way to correctly clean the piston/caliper is to remove the piston and seal clean the piston in brake cleaner remove the seal and clean it with isopropyl alcohol, then use the brake rebuild seal lubricant on reinstallation /. But since you got this far it would be better to just rebuild the calipers and fit new seals and pistons if they are damaged as well as inspecting the piston bores, Stan

Tony

Darien, that tool we used to fill the tranny fluid is a brake bleeder also... it comes with a cap that goes on the resiviour.
Get some new fluid and flush and bleed the system.

hacker-pschorr

Truechoice, in Ohio used to have them on their web site. I spoke to one of their reps, if the parts are available through Brembo, they can get them. Problem is, we need Brembo part numbers. They have no way of looking up "1987 928 S4 Caliper".

928 Specialists can get the kits with the piston - wonder if they are packaged with individual part numbers to research getting new seals? This is frustrating, the S4 is not the only OEM car to use these calipers.

Bill Ball

Yeah, we need seal and boot PNs.

AO

There should be a Brembo casting number or part number on the caliper. Should be able to reference that, perhaps?

hacker-pschorr

Place I spoke with needs the actual part number for the seals. Many variations of piston size in this size caliper were produced.

Bill Ball

I was sure I had a seal and boot kit uninstalled with the parts in Porsche baggies and went looking for it last night in the garage. Couldn't find it. Need to look some more.

hacker-pschorr

If you find it - that Bill Ball tribute thread is going to gain some momentum.