Plating calipers without splitting???

ManniB · 02-07-2015, 11:46 PM

Hi,

one of my next projects will be rebuilding the brake calipers on my '80 SC. The most thorough way would be to split the calipers and have the halves cleaned, sandblasted and plated. However, it looks like the seals for at least the rear calipers are not available.

As an alternative, I'm thinking about having the calipers plated WHITHOUT splitting the halves. In the past, I have had several other parts plated that contained some rubber/platic parts and it didn't seem to cause a problem.

Anyone attempted this with success?

Thanks, Manfred

chris_seven · 02-08-2015, 03:06 AM

Manfred,

There are one or two issues to worry about.

The first is will you be able to clean the oil passages successfully if you don't split the calipers as the plating or chromating solution could be trapped.

We always clean these passages very carefully after plating.

The second is the bolts which are very high strength and could have issues with hydrogen embrittlement unless they are baked after plating.

We don't tend to re-plate these bolts we clean them and use a cold-blacking system that doesn't cause any problems.

I recently ordered seal kits for all of the ATE calipers from their importer in the UK and they all arrived without problem.

If you can't get them from ATE then Budweg in Denmark supply them again them through their importer.

The only part you won't find in the kit is the inner seal that joins the two halves which is a square section O Ring.

We had about 500 made in EPDM 2 years ago and have plenty.

wolds · wolds's Garage

Manfred, I split and rebuilt the calipers for my 83SC a few years back and accessed parts including those square section rings from Eric at PMB (use link to access his site). Shop PMB - Catalog Not right around the corner for you, but PMB is the go to brake guy here in the States. Warren

Robbbyg · Robbbyg's Garage

i kept mine together, masked off areas, used dremel on lines AND BOLTS THEN SEALED WITH SILICONE TUBING came up ok, mine is a daily driver , so the goal was rust protection before beauty, but came up alright, i used ceramic paint, car is a 77 930 l did these a year and 40000 kays ago. The Ceramic paint is TOUGH

sory for caps am writing this while wiring under car lol

Robbbyg · Robbbyg's Garage

u can see the cleAr tubing in this pic,
protection and u can see fast where prob is, but obv not as good as having them rebuilt professionally

shrtshck · 02-08-2015, 08:20 AM

Just finished assembling my 87 calipers yesterday, as noted by others the good folks at PMB provided the seal kits. Before setting out read the DIY rebuild write up posted on the PMB site as well as the one posted on the Pelican Tech info area. The significant area of concern is the odd ball ribe bolts used, in my case M7 and M9 which are not available anywhere from anyone. Before disassembling clean the threads protruding from the nuts and lube well with penetrating oil. I purchased a Ribe socket set from my nearby Napa, it took a few hours for them to locate one and it had to ordered in. As noted in the write ups do not cheap out and attempt to use any other style socket.

I had a local plater clean up and zinc coat the calipers, he used glass bead blast rather than sand blast as he felt it would provide a better surface finish. Since they were disassembled he could clean the drilled passage ways with a pipe cleaner after each step.

Pictures of the results below, cant wait for spring to get back on the road;

LM3929 · 02-08-2015, 08:37 AM

I Have bought the inner O rings from Pelican a couple of times now and the caliper kits as well

at not a bad price

Lorne M.

shrtshck · 02-08-2015, 11:23 AM

I too have purchased piston seal rebuild kits from Pelican, but was under the impression that the only source for the o-rings required when splitting was PMB, if that is not then case then my bad.

LM3929 · 02-08-2015, 03:22 PM

Consider your self spanked and sent to the dog house

oh I should have know Ontario ....how's the snow

Lorne M.

shrtshck · 02-08-2015, 04:24 PM

Snow is just fine, it's the freezing rain that I could live without ;o(

LM3929 · 02-08-2015, 05:14 PM

Sorry to hear about the freezing rain but as soon as I get back in from cutting the grass I will get the part number for the Flat cut O rings.

Lorne m.

ManniB · 02-10-2015, 07:44 AM

Hi,

thanks for all your replies to my question. As I understand, the inner seals for the rear M caliper are still available from Porsche as 901.351.928.10 or VW pn 311.615.277. For the front A caliper I have ordered eight seals from PMB. The best thing is they send them out by snail mail so its ony $6 for shipping (usually UPS costs an arm and a leg for shipping to Europe).

- Manfred