Cleaning brake calipers

[Monkeythree]

Any tips on how best to remove 22 yrs worth of baked on dust and grime from my rear calipers? Tried Wynns brake and clutch cleaner and it has minimal impact even when accompanied with vigourous brushing (plastic bristles). Is there a magic bullet?

Have given up for now and turned my attention to rectifying the plate lift. The small dome head allen bolts are siezed tight so this job is probably going to end up taking a lot longer than expected.......

 

[Paul190H]

I had the same issue and used similar products and shed loads of elbow grease. As for the domed nuts, I soaked mine in penetrating oil and then used a sharp chisel and hammer to get them started, followed by lots of patience. I have made a concious desicion to clean mine yearly to prevent the same issues happening again. Good luck.

 

[spyderman]

Send them away to have them properly refurbished. Bet the seals are all knackered too, so worth doing.

 

[zcacogp]

M3, Can't help much with the cleaning but I use copious amounts of Bilt Hamber Surfex on the greasy bits of my car and it has yet to let me down. Link here: http://www.bilthamber.com/surfex-hd I notice you are in Sweden so don't know how available such stuff is out there. If you are rebuilding the calipers then this page may be helpful; http://www.porscheclubgbforum.com/tm.asp?m=626776&mpage=1&key=caliper All the best. When working correctly, the brakes on an S2 are astonishingly effective. Oli.

 

[Monkeythree]

Oli, Thanks for the link to your earlier thread on the subject. I actually ended up taking my calipers to a local re-con specialist in Goteborg this afternoon because my dome headed bolts weren't shifting. The calipers are actually in really good condition so I didn't want to risk damaging them whilst trying to remove those bolts. So the specialist is just going to remove the bolts ( not sure how but he seemed totallty unfazed by them), do a bit of local shot blasting of the corrosion under the plates, straighten the plates and put it all back together with a 24hr turnaround. All for £100 which seems acceptable. And if they come back clean, that will be two jobs in one!

 

[zcacogp]

M3, Great. It seems that engineering shops have magical powers they can call upon to remove badly stuck bolts that us mere mortals don't have. They will probably weld a bolt to the head of the existing one, which will both give them something to get a purchase on to twist it out and also the localised heat will free the remains of the existing bolt. Shot blasting can be a bit aggressive for a (comparatively) soft aluminium caliper. I hope they go gently. More normal would be a sand or bead blast. £100 is a good price for doing that to two calipers. Oli.

 

[Monkeythree]

I could have welded on a bolt (actually i would have sacrificed eight 4mm allen bits) but it took me 30 minutes of picking and scraping and flushing amd brushing to expose the allen head on the first bolt before establishing it was seized - i would have been there for days! The guy said he was going to split the calipers to get better access to the bolt heads. Not sure how he will do that when the two halves are joined by the ss plates but lets see. He does nothing except reconditoning calipers so i'm hopeful he knows what he is doing. He had certainly seen Porsche brembos with plate lift before!

 

[Eldavo]

I'm just reconstituting things I've read here but I'm pretty sure that there was a thread recently about this and the advice was NOT to split the calipers!

 

[Monkeythree]

I was a bit worried about that too but the calipers are in the hands of these guys: [link]http://www.bromsok.com/[/link] A professional outfit and when I discussed the job with the owner, he was perfectly confident about it. I'm not concerned that there will be any functional issue resulting from splitting the calipers, but the irritation for me now will be that it will disturb the paint around the bolt heads and along the join which will inevitably lead to corrosion starting.

 

[Monkeythree]

Got my calipers back from the specialist and my plates now look like this:

Took a plate off to have a look at how bad it had got underneath before my intervention:

Will be removing all the plates and give the exposed areas some suitable protection before re-assembling. As a bonus, the calipers also came back entirely clean of all the grot that had proved so stubborn to remove in the first place!

 

[zcacogp]

That looks like a nice job but - as you say - some unguent underneath those plates is essential. Copper grease, silicone sealant, anything at all. Chewing gum, perhaps ... I have split my calipers in the process of cleaning them up. There are dire warnings in the manual bout not doing so, but it was no biggie and I couldn't see what the fuss was about. I called my indie up to make sure and he couldn't explain the dire warning either. My calipers have worked fine for 7 years / 70,000 miles since, so I presume I didn't ruin them. Oli.

 

[Monkeythree]

My plan is to fill in the pitting with some sort of suitable putty then paint the exposed areas so they are not exposed to air or water then use a layer of high temp sealant under the plates. As per your prior thread on the subject really. I expect that someone in the Porsche engineering department probably recommended that sealant was used as OE but then someone in the Porsche finance department did the sums and proved that the additional cost in production was higher than the probable lifetime warranty costs of omitting it and therefore won the argument. That's usually the way it works in automotive!

 

[robdimond]

I read the dire warning about not splitting the calipers and so avoided it when doing mine. There is plenty of access to weld a nut on without splitting the caliper and that's my preferred method for getting the bolts out. That said, the calipers clearly don't explode into a million pieces if you do, and a professional outfit probably has the torque settings/jigs/know-how to do it properly. You are lucky to have the later calipers with the rubber dust boots. Worth considering replacing them (and the pistons if corroded) because they are not too expensive, as opposed to the early scraper seal calipers which are basically unserviceable.

 

[zcacogp]

ORIGINAL: robdimond You are lucky to have the later calipers with the rubber dust boots. Worth considering replacing them (and the pistons if corroded) because they are not too expensive, as opposed to the early scraper seal calipers which are basically unserviceable.

The early ones aren't unserviceable but are very expensive to service. I bought a new piston for one of the front ones on my S2 and baulked at the £40 price tag. Pistons for the booted-type are nearer £10. Oli.