Jacko 2158 Report post Posted August 15, 2019 (edited) Has anyone come across a source for stock replacement OEM pistons? I cant find a part break down for them anywhere.. Going to rebuild these, new seals etc etc. Some of the ceramic insulators on top of the pistons are starting to crumble, not horrifically but a couple are missing chunks. Cant really justify blowing 4-500 USD on stoptech/racebrakes stainless pistons, but new OEM ones might be an option? Edited August 15, 2019 by Jacko Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted August 18, 2019 Toasted ceramics (and seals), still hunting for p/n of OEM pistons, no joy. Quote Share this post Link to post Share on other sites
M3AN 4016 Report post Posted August 18, 2019 (edited) Man, they're really screwed, how are the bores because those pistons are seriously marred? My 150k kms brakes still had intact seals and perfect pistons... and no fancy ceramic insulators... that don't look like they do anything meaningful except break down. IIRC I could get new pistons from BMW even though they weren't listed in the ETK, did you try them? What size are the pistons? Edited August 18, 2019 by M3AN Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted August 18, 2019 I guess the dust seals have been gone for a while, everything below the piston seal looks fine, just black grime above it. Nah havent tried BMW directly yet, will do tomorrow. 28/32/36mm Quote Share this post Link to post Share on other sites
M3AN 4016 Report post Posted August 18, 2019 Here they are, cheap as chips too. Available in 28, 32 and 36mm... I selected 2012 135i but you might want to have a play. https://www.carid.com/centric/replacement-caliper-piston.html 1 2 Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted August 18, 2019 Kick ass, Ive been hovering around the centric site and found the rear end 42mm piston but nothing else. Thanks! Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted August 26, 2019 Hmm 2 Quote Share this post Link to post Share on other sites
M3AN 4016 Report post Posted August 26, 2019 ?????? Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted August 26, 2019 Never tried youshop... but its on the way to oregon for $10... Which seems like a better deal. Lady on the chat support couldnt understand why I thought $1600usd was unreasonable. 1 Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted September 1, 2019 FYI, pistons are also listed on rockauto.com, pretty sure they are centric branded as well, similar pricing (cheap). Will be interesting to see how they are constructed - chrome steel+ceramic like OEM, or all stainless like ($500USD) Race Brakes, or aluminium like ($400USD) Stoptechs... Quote Share this post Link to post Share on other sites
M3AN 4016 Report post Posted September 1, 2019 (edited) Unfortunately perhaps, but my recent dive into E87 forums indicates these 6-pot Brembo/BMW calipers are the work of Satan and suck balls. Apparently that's why BMW "upgraded" to the later 4-pot fronts. Evidently the seals fail prematurely and then cook the pistons, some have taken the calipers off at 1000 kms and found perished seals! If I were you Chris I'd be looking for upgraded seals (not sure if they're available) or you'll be replacing pistons again soon enough. This sort of poor quality sh*t should be a legally mandated recall and permanent fix in my opinion, regardless of the cost to BMW. They're brakes for crying out loud, they're more important than airbags. Edited September 1, 2019 by M3AN Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted September 1, 2019 Seals on these were still fine, dust covers were destroyed and so were the ceramics. Apparently they suck on track with stock pistons which fail as soon as you put a few heavy heat cycles in them..but are fine with solid pistons. I saw a few companies do high temp silicon dust covers, which take the heat but implode on contact with brake fluid Plenty of 130 race cars are running the old style brembos without issue (with one piece pistons). All these OEM BBK calipers go for stupid money in NZ, E's or F's, I swear some wreckers recoup the price of the car they purchased just by selling the calipers. I got these for cheap... The other issue with the F series calipers is there isnt really an option for the rear end, trimming the pads and running an E39 M5 rotor apparently works... but doesnt seem ideal. I doubt the pistons I have coming are ceramic/two piece, Id be impressed if they were for $10 each Quote Share this post Link to post Share on other sites
M3AN 4016 Report post Posted September 1, 2019 Single piece pistons seem far smarter to me here, clearly the ceramic 'solution' in play is less than perfect. Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted September 4, 2019 Centric piston, 1 piece ali (made in Canada aye) The centric dust covers are grey silicon Vs OEM black nitrile, which is also promising. 1 Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted September 22, 2019 Stumbled over a thread on the internets that mentioned the BMWP calipers have ali pistons Vs the 135i calipers steel/ceramic. Which might explain why the BMWP calipers do exist as an upgrade for the 135i, other than the slotted/drilled rotors (and the paint) Finding part numbers for these things is absurdly difficult for a "modern" car, spent hours trying to find the bolts for attaching the caliper to the bracket, as Brembo keep it top secret, M12 1.5m x 72mm with a socket head... For anyone referencing this in the future - Porsche p/n 99907340201 Was curious what the "lumps" bolted to the outer edge were, so took em off, they're steel so Im assuming some sort of harmonic dampener. Quote Share this post Link to post Share on other sites
mzhu031 38 Report post Posted May 6, 2020 did the seals come with the pistons? or did you buy them separately? Just in the process of rebuilding the set I got, the ceramics fall off as soon as you poke them.... Quote Share this post Link to post Share on other sites
Jacko 2158 Report post Posted May 6, 2020 Separately (grab new boots too) 1 Quote Share this post Link to post Share on other sites
