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4x32 M635 front brake pistons

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K1W1
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Joined: Fri Aug 24, 2018 12:30 am
Location: Auckland New Zealand

4x32 M635 front brake pistons

Post by K1W1 » Tue Apr 16, 2019 11:11 pm

Hi - at least some of mine .... are a bit shabby. Struggling to find a supplier. Any suggestions please ? I'm in NZ but also in the USA every 6-7 weeks.
Thanks Julian

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nick88highline
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Location: Suffolk, UK

Re: 4x32 M635 front brake pistons

Post by nick88highline » Wed Apr 17, 2019 12:14 pm

When I rebuilt my single pot calipers I had stainless steel pistons made up, but then I only needed four to cover the entire car :D
I used a UK based company called Kitek. I guess there must be somewhere closer to you that could do that, but it would not be cheap.
BMW does not sell the pistons on their own, at least for my calipers, so having them re-made was my only (sensible :lol: ) option.
Nick
BMW 635CSiA (1988)
BMW i3 (2016)
Jeep Grand Cherokee V8 (2000)
Morris Minor 1000 (1968)

K1W1
Posts: 16
Joined: Fri Aug 24, 2018 12:30 am
Location: Auckland New Zealand

Re: 4x32 M635 front brake pistons

Post by K1W1 » Thu Apr 18, 2019 4:05 pm

Thanks Nick I think I've found a solution

https://www.ebay.com/itm/BMW-6-SERIES-E ... 0#viTabs_0

bpoliakoff
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Re: 4x32 M635 front brake pistons

Post by bpoliakoff » Fri Apr 19, 2019 9:32 pm

Kiwi For kicks I just googled Big Red Ltd and you can get to them directly and avoid Ebay if you haven't done so yourself. Probably more economical as you can save them the ebay fees at the least. Just sayin1
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.

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zinnocoupe
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Re: 4x32 M635 front brake pistons

Post by zinnocoupe » Fri May 03, 2019 7:52 pm

Thats an interesting product. I assume that front calipers on the M636csi are different from Series I four piston calipers.I should know this but can't remember. I just measured a piston from my 530i and it is 42x30. I see they have the later 635csi single piston kit as well.

Edit: According to realoem those pistons were used on all all these models:

1502-2002tii   (09/1968 — 11/1975)
1500-2000CS   (09/1963 — 01/1972)
5' E12   (02/1972 — 07/1981)
5' E28   (10/1984 — 01/1988)
2.5CS-3.0CSL   (12/1968 — 11/1975)
6' E24   (10/1975 — 04/1989)
2500-3.3Li   (08/1968 — 02/1977)
7' E23   (10/1976 — 06/1986)
M1 E26   (06/1980 — 07/1981)

So that 40x32 must be a typo, they meant 42x30.

Its good news for people with rusty old series I brakes
Image
1979 Euro 635ci no longer a basketcase, just a running rust bucket!
1977 530i New addition ( nonrunner)
1987 635csi 60K KM Garage Queen

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zinnocoupe
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Re: 4x32 M635 front brake pistons

Post by zinnocoupe » Wed May 08, 2019 5:43 pm

OK please disregard my last post. I just realized I was measuring a set of rear pistons which are a different size :oops:
Image
1979 Euro 635ci no longer a basketcase, just a running rust bucket!
1977 530i New addition ( nonrunner)
1987 635csi 60K KM Garage Queen

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