ATE caliper pistons...

[Ed Miller]

i got the vernier caliper from the mail and I can confirm that the ATE caliper pistons I removed are in fact 1.415" as

the site reccommended by Ed miller - http://etypeparts.myshopify.com/products/ate15-bmw1


So pretty good price for the pistons. Cheaper than we have to pay in England.

Thanks, Arvo.  I don't know when I should rebuild mine again but I'm tempted to get them now anyway, in case the guy closes shop before I'm ready.  I stock up on other odds and ends for my R65.  I guess I'm stuck with it for life.

[arvo92]

nearly 40 quid at motorworks! wish i'd access to a lathe! lol

I am the idiot who actually paid that money for a set of 4! Oh well, better 150 pounds than crashing again. Now I am just waiting for them, Motorworks does not have them in stock and it takes a few odd days for them to arrive.

Ed - jup, better stock up so you do not have to pay twice the amount in few years. As far as I have read calipers should last for 3 decades if greased and maintained regularly. So one purchase should last until the  end of the bikes life.  

Barry - my digital caliper read me 1.417" reading when I measured. The difference is so sublte that by pressing Vernier caliper very tightly around the caliper itselt, I could get a 1.415 reading. I just thought that that is the measuring error.

[Bob_Roller]

I guess I'll remove the calipers and replace the seals from my '81 R65, never been touched since it was assembled in September, 1980 .

Been putting this off for a long time !!!

Don't know what to expect, 12 years of use in Chicago and the last 21 years in Phoenix .

I have a set of Brembo calipers, if things went real bad with these .

[livingdeadhead]

set of 4? mines a single disc 79 i only need one , we are talking ate's here?

[Bob_Roller]

The '81 model year North American bikes came with dual discs, ATE calipers, early '82 model year LS bikes had ATE's as well .

It was available as a dealer installed option as well .

You do need two, as there is a piston on each side of the caliper .

No matter what caliper you have, ATE or Brembo, they both have two pistons

[Barry]

set of 4? mines a single disc 79 i only need one , we are talking ate's here?  

They came with s single disc. A 2nd disc was always an option and maybe fitted in some markets or to shift them off the sales room floor.

[livingdeadhead]

only been checking the pads thickness up to now , if it works leave it alone , be nice to have some as spares tho £80.00! , do they do one made of steel ? surely these are made of gold hand rolled on the thighs of virgins?

[Barry]

if it works leave it alone  

I must admit regular brake fluid changes aside I take that approach with my 25 year old car because replacing all the pistons would be a major exercise.

On the bike though there may be some merit in early intervention. What I found on the bike is the corrosion starts from the outside under the dust seal and travels inwards towards the part of the piston surface that contacts the piston seal. No amount of regular brake fluid changes will help stop corrosion under the dust seal but if you can catch them early enough the corrosion can be polished out and the pistons saved. The dust seals can then be refitted or replaced with an application of brake grease underneath in an attempt to  keep the corrosion at bay.

[Luca]

I'll be rebuilding the calipers on my 94 miata very soon.  I had pulled out one dust seal to free up a stuck piston and it can't go back in without the piston removed from the bore!

When I rebuild I'm going to pack a little bit of brake grease underneath the dust cover to help discourage corrosion on the piston.  I'll replace that piston, though... I can get one from rockauto for less than $10 8-)

[livingdeadhead]

i use red rubber grease , renolit i think its called doesnt make seals swell ,good stuff can pack your seals with it , doesnt comtaminate brake fluid either

[montmil]

Off topic

Luca, I'm a fan of Rock Auto, too. Mucho bucks saved on the F-150 and Cabriolet.

[tvrla]

My 1978 3/4 ton Dodge Van had hard black plastic caliper pistons - something like Bakelite , if that tells you anything. Stainless or anodized aluminum will work just fine. What Tony says is true! Next time I need some, that's probably the route I'll take - turn some on my dinky HF lathe.

[nomis1968]

Howdy everyone, this is my first post.

I am an engineer with access to modern machine tools

I have  recently made a set of these pistons from 304 stainless steel. It is easy to get the correct size and finish on the lathe with some polishing.
I made these for a friend who has fitted them to his caliper and then sent his bike for MOT.He is very happy with them!

The originals were chrome plated to give some protection against corrosion. These were then centreless ground to true up the size because chrome is too hard to be machined on a lathe.

The problem with the originals besides the cost is that eventually the steel corrodes under the chrome, the plating lifts off the surface and damages the seal.

Stainless steel replacements are an excellent upgrade.
If there is enough interest i can run off a few sets on the CNC lathe.


In the mean time I have listed a batch of these pistons on Ebay if anyone is intrested?

I can't post an active link here but if you search for them under BMW R45/65 ATE brake pistons you will find them

If anyone can think of any other machined parts that are ridiculously priced get in touch i can manufacture almost anything at resonable cost for other members.

[Bob_Roller]

What diameter dimension did you use

[silencio]

I think that's the US guy's new web page, hopefully a direct link to the R65 piston.  Does that measurement look right?  Arvo, it looks like you have some handy to measure.

Thanks for the link. You say these are stainless? I couldn't find any mention of material on that page.