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Brake calipers question

Posted: Wed Feb 07, 2018 1:12 am
by BMWFanatic2008
Hey guys,

My driver's side rear brake caliper started leaking brake fluid. I took the car to a local mechanic and he recommended replacing it. He isn't sure if it can be rebuilt due to its age/rust.

I looked up the part number and it's 34211119211 (my car was built before 9/82). Any idea where I can purchase a rebuilt one? The new ones are expensive, around $300.

Also, do you think I can fit one from 82+ model (will replace both sides in this case)? I found plenty of those available at a reasonably price.

Thanks in advance,
Andy

Re: Brake calipers question

Posted: Thu Feb 08, 2018 5:15 pm
by Brucey
the later caliper won't fit over your disc. There are parts bin options for converting both disc and caliper to a different spec but I would suggest that you stick with the standard (E12 chassis) fitment if you can.

IIRC the calipers use a piston size and seal/boot design that is common to other calipers so you ought to be able to get the caliper rebuilt or exchanged without having to buy a new one.

A seal kit is likely to be just a few quid if you fancy DIY and here in the UK companies like Bigg Red offer exchange rebuilt calipers at reasonable cost.

cheers

Re: Brake calipers question

Posted: Thu Feb 08, 2018 10:27 pm
by BMWFanatic2008
Brucey wrote: Thu Feb 08, 2018 5:15 pm the later caliper won't fit over your disc. There are parts bin options for converting both disc and caliper to a different spec but I would suggest that you stick with the standard (E12 chassis) fitment if you can.

IIRC the calipers use a piston size and seal/boot design that is common to other calipers so you ought to be able to get the caliper rebuilt or exchanged without having to buy a new one.

A seal kit is likely to be just a few quid if you fancy DIY and here in the UK companies like Bigg Red offer exchange rebuilt calipers at reasonable cost.

cheers
I see, thanks for the info. I will keep looking for a refurb. one then.

Re: Brake calipers question

Posted: Wed Mar 07, 2018 11:56 pm
by BMWFanatic2008
Ended up rebuilding the rear brakes myself. The pistons were completely seized on one of the brakes so only one side was working. Will be doing the fronts next. Took a bit of time to find the correct replacement parts for e12 based brakes but the result was well worth it :D

Here is what I had to buy:
Brake caliper repair kits
Brake pads
Brake wear sensors
Pins and brackets
Paint

Big thanks to this forum (found a couple of very useful DIYs on here).

Re: Brake calipers question

Posted: Thu Mar 08, 2018 10:28 am
by Brucey
looks good!

cheers

Re: Brake calipers question

Posted: Tue May 15, 2018 12:07 pm
by BMWFanatic2008
Hey guys,

I have a follow-up question re: brakes. I am looking to purchase a brake lines kit for my car. I found a few listings on ebay for APEX kits. Do e24s based on e12 chassis and the ones based on e28 chassis share the same brake lines? The ebay seller is offering the same kit for all 633 model years (78-84). I know the brake calipers are different so wanted to make sure. I have pre-82 production 633.

Anything else I should consider / purchase for this job?

Thanks.

Re: Brake calipers question

Posted: Tue May 15, 2018 3:37 pm
by GRNSHRK
That doesn't sound right, fanatic [-X

The E12 front brakes are 4 piston fixed calipers, but the E28 does not =;

Dang, thought you could see the 2X lines going to the caliper in this photo, but you can see the 2 rigid/fixed pipes :roll:

Think I would continue your search :-({|=

Re: Brake calipers question

Posted: Tue May 15, 2018 5:37 pm
by BMWFanatic2008
GRNSHRK wrote: Tue May 15, 2018 3:37 pm The E12 front brakes are 4 piston fixed calipers, but the E28 does not =;
Hi GRNSHRK,

So E28 based front brakes have only 2 pistons? The kit comes with 6 lines according to their description. I assume that's a good indicator that it's for E12 based car?

Re: Brake calipers question

Posted: Tue May 15, 2018 6:33 pm
by GRNSHRK
I think the E28 calipers (front and rear) are only single piston floating type :-?

But looking at your rebuild photos of the rear, I can now see that those are indeed E12 calipers, which are actually 2 piston fixed type =D>

Bottom line, the correct kit should have a total of 6 lines for the E12 chassis [-o<

It's possible that this seller throws in enough for both E12 and E28 chassis, but I have no idea if the fittings are the same, lengths are compatible, etc. :-?

BTW, nice rebuild job in your photos \:D/

Here's a shot of mine #-o

Re: Brake calipers question

Posted: Wed May 16, 2018 12:49 am
by BMWFanatic2008
GRNSHRK wrote: Tue May 15, 2018 6:33 pm I think the E28 calipers (front and rear) are only single piston floating type :-?

But looking at your rebuild photos of the rear, I can now see that those are indeed E12 calipers, which are actually 2 piston fixed type =D>

Bottom line, the correct kit should have a total of 6 lines for the E12 chassis [-o<

It's possible that this seller throws in enough for both E12 and E28 chassis, but I have no idea if the fittings are the same, lengths are compatible, etc. :-?

BTW, nice rebuild job in your photos \:D/

Here's a shot of mine #-o
I see, thanks for the info. I think I will take a chance and risk $60 and if it doesn't fit, I will return it. A few other kits that I saw are a lot more expensive.

Very nice setup you got! Hopefully mine will look the same at some point in the near future.

Re: Brake calipers question

Posted: Wed May 16, 2018 3:33 pm
by GRNSHRK
Thanks :lol:

The caliper paint has held up very well, can't say the same for the rotors, which of course have rusted where the pads do not contact them :oops:

Good luck with your project, please post pix when she's complete [-o<