Who still sells Stainless brake pistons?

[tjones02]

Who still sells Stainless steel brake caliper pistons for 2002 and Tii calipers?? Anyone???

I am trying to answer this guys question but can't find who still sells these.

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,336757/

Thanks!

[DavidLMM]

Think Korman used to, but only saw the E30 M3 application when I looked earlier, trying to do the same.

Maybe they still have the tooling, but not enough demand to list?

David

[Lee]

Bigger pistons for the e30M3 and e36 M3 are available from AKG too.

Pistons are perhaps from imperial size (like hydraulics). Then perhaps they can be sourced from Wilwood in 1.375" (34.93mm), 1.625" (41.27mm) or 1.75" (44.45mm)...

[chipperwerks]

Thanks for pursuing this Tom! I am weighing my options.... One might be to go with rebuilds, or Volvo caliper combo or finding an old unwanted caliper and donating it's pistons ..... Up in the air. Thanks again...-chip

[jerry]

for this application, stainless steel MAY not be the best solution.

as for rust prevention, you are only addressing one side of the problem, but sacrificing another equally important feature of the original component.

Note that the cylinder BORE is still non-stainless and subject to rust with or without SS pistons.

Also, if you look closely at OEM pistons, it appears that they are chrome plated on the piston walls. Chrome is very wear resistant and capable of acheiving a very fine surface finish.

Additionally, they appear to be a cast iron (perhaps ductile iron or grey cast iron) which has a slightly lower coefficient of thermal expansion (CTE) than plain carbon steel, and i believe SS.

i would be reluctant to exchange a chrome-plated wear resistant surface for a less wear-resistant SS of the 300 series (typical) unless perhaps it was made from a hardenable 400 series.

just my thoughts on the subject...

[TobyB]

Note that the cylinder BORE is still non-stainless and subject to rust with or without SS pistons.

but the beauty of the design is that the finish of the bore is only critical

in the sealing groove- the rest, as long as it is dimensionally supportive

of the piston, just doesn't matter so much.

It might be heavy, but it works well.

And yeah, the chrome plating is pretty darned good, too.

t

[tjones02]

for this application, stainless steel MAY not be the best solution.

as for rust prevention, you are only addressing one side of the problem, but sacrificing another equally important feature of the original component.

Note that the cylinder BORE is still non-stainless and subject to rust with or without SS pistons.

Also, if you look closely at OEM pistons, it appears that they are chrome plated on the piston walls. Chrome is very wear resistant and capable of acheiving a very fine surface finish.

Additionally, they appear to be a cast iron (perhaps ductile iron or grey cast iron) which has a slightly lower coefficient of thermal expansion (CTE) than plain carbon steel, and i believe SS.

i would be reluctant to exchange a chrome-plated wear resistant surface for a less wear-resistant SS of the 300 series (typical) unless perhaps it was made from a hardenable 400 series.

just my thoughts on the subject...

Yes but try and find anything but used or stainless pistons. BMW doesn't sell the pistons separately...

[Lee]

Stainles steel pistons are much better than any aluminum or chromed pistons.

Stainless will act as a heat insulator. It will not corrode and will not scratch as easily. I suggest looking at Wilwood's website, or on eBay for some stainless steel cup pistons.

[jerry]

Stainless will act as a heat insulator.

care to explain this?

per tom's comment, it appears that this is a moot subject anyways as OEM pistons are not sold separately.

my position is merely that SS may not be an upgrade from OEM type but is certainly a viable alternative when one needs to replace a damaged piston.

[Lee]

Aluminum or steel pistons are the worst material as they carry heat from the pads to the fluid just too easily, allowing fluid to boil. Also, chromed pistons get pitted if fluid is contaminated with moisture. Ever wonder why true race calipers use titamiun or stainless steel?

If replacement pistons are required, then have them machined from any 30X stainless.

[Mike Self]

an outfit in VA called White Post Restorations (White Post, VA) will rebuild your calipers by boring 'em out and sleeving them with brass sleeves back to standard size. (http://www.whitepost.com/brake.html )

They return the calipers will all new rubber parts and a bore that won't rust again...

Good craftsmen. I've visited their shop--they also restore antique cars...

Cheers

mike

[Bill_Riblett]

an outfit in VA called White Post Restorations (White Post, VA) will rebuild your calipers by boring 'em out and sleeving them with brass sleeves back to standard size. (http://www.whitepost.com/brake.html )

They return the calipers will all new rubber parts and a bore that won't rust again...

Good craftsmen. I've visited their shop--they also restore antique cars...

Cheers

mike

I had White Post rebuild the calipers and master cylinder for my 2000CS, as these parts have long been NLA and I did not want to screw around trying to swap something else.

They did nice work and they have a lifetime warranty, which I had to use when a seal failed on mine. The only problem I had at all was it took them a while to find seals.

I've been on a couple of tours and it is an interesting place. No telling what you will find there. They actually have on worker who only rebuilds the hydraulic parts, as they do lots of them.

[jgerock]

As Bill Riblett mentioned, White Post Restorations in VA has a very good reputation (and seems to charge plenty for their services). They are a long-time advertiser in Hemmings for hydraulic system work.

Be careful what you ask for when specifying stainless steel parts. 300 series is better at corrosion resistance than 400 series. The higher the series, the higher the carbon content in the metal.

One customer of ours specified 420 S/S for some special plates that mounted on his injection molding machine. We hesitated, then supplied what they wanted. The parts oxidized very fast. We wanted to supply 304 S/S which is our standard.