Dan Martinic

I have decided to address a long-running brakes issue: my original Brembo calipers have that aluminum corrosion "bloom" under the spring plates; some almost none, some enough to push up the plates.

A shop on the other end of town that specializes in caliper rebuilds and has done many Porsche is quoting 150 CDN per caliper. I have removed all four and I'm considering putting them back in service mechanically sound myself (appearance is not a priority right now). The pads are wearing evenly.. the seals all seem fine.. I just need to grind down new pads far too much to fit and feel like addressing this now.

1. How do you clean calipers covered in thirty years of crud and avoid damaging existing seals? Can you spray any solvent and brush away? Can you soak the things in a parts washer?

2. Can you remove the spring plate screws with a propane soldering hardware-store torch or do you have to use the pro Acetylene setup?

3. If I do manage to clean & remove the spring plates myself, what is the latest on re-assembly sealing product advice (ie. stuff to put under spring plates) to prevent re-corrosion?

Thanks,
Dan

Jay Wellwood

In response to #2 - I used MAP Gas to heat the cap screw up then used the allen wrench to break 'em free. For the one that decided to strip - I cut a slot in it and removed it using a short slot bit.

In response to #3 - I first used a plastic putty knife to remove the loose corrosion, then used a small stainless wire brush to remove the last of the debris/corrosion products. Then I wiped down the area using alcohol. Keep in mind that if you don't seal the aluminum, you'll get a small layer of oxide on it. Once reassembled, the SS springplate and aluminum arer a perfect combination with a little moisutre present to start the corrosion process in real earnest. Need to seal the aluminum.

Dan Martinic

Porsche has quoted me $74 CDN per spring plate; that's 150 CDN per caliper! I forgot to ask if the screws are included!

I've decided to go with the rebuilding option that I found.

Breakaway944

You should be able to buy a map/oxygen torch at home depot (canadian tire?) That looks like this

This type of torch will put out enough heat - you are trying to heat up a small screw that is screwed into a giant heat sink. You need a lot of heat fast to melt all the loctite.
The mushrooming is caused by galvanic corrosion of dissimilar metals. You need to isolate the stainless from the aluminum. Paint, powder coat or some type of non metalic barrier. All barriers will eventually fail, the factory powder coat after many years and miles failed allowing the stainless to touch the aluminum.
I would change, or at least have on hand, the dust seals for the front calipers. I ended up ripping them on both front calipers (the large piston) trying to get the plates back on, not enough room.

Jay Wellwood

FWIW - you should be able to return the spring plates back to their original physical configuration. To restore the surface finish, I used a small wire wheel on my dremel tool. YMMV

Dan Martinic

So that's what a map torch is... thanks for the pic. I might grab one anyway.

As for the calipers, given the cost of parts and liklihood I --like you-- will need them, might as well hand them over for rebuilding for the same money.

Dan Martinic

Two of them are pretty bad... look twisted! I guess I could try. The dust seals... are they easily available? Then again, something tells me "rebuild now before these 30 year old things fail again" like water gets in etc

It's the same voice that tells me "instead of fixing the leak, replace the leaky faucet with a shiney new one".

I hate that voice

Jay Wellwood

Dust seals are available and reasonably priced IMHO.