Just fitted BMW front calipers to my 411

kps70 · Post by **kps70** » Sun Sep 13, 2009 2:37 pm

The BMW E21 ATE calipers fit my 411le variant and they work a treat. I had some problems fitting them, the usual stuff I guess?
a) All the brake lines needed replacing as they broke when I took it apart. Beetle 1303 flexible hose was used.
b) The wheels fouled on the calipers so I needed to get spacers
c) the bleeding took so long I thought it was the master cylinder so I changed it for a spare I had which added a couple of hours to the job.
d) I had to take the calipers off, turn them 'upside down' i.e. the right way up and bleed them that way round (the BMW calipers go on upside down leaving the bleed nipple at the bottom and the air just did not want to shift from them in situ)
Here are some pictures:

I can now go into a corner without having to lift off the accelerator about half a mile in advance! Happy days. The brake balance seems fine. I guess time will tell if the master cylinder is up to the job. Will keep you posted if I have problems.
Kieron
ps. 'Hi' to all fellow American type 4 nuts!

perrib · Post by **perrib** » Sun Sep 13, 2009 5:26 pm

Nice conversion. Did you use copper tube for the lines.

Post by **Piledriver** » Sun Sep 13, 2009 11:53 pm

The European brake line tubing is copper plated for corrosion resistance.

This side of the pond it's galvanized for the same reason.

Are you sure you can't flip those calipers side to side and get the bleeders on top? (I can't see the pics at work...)

The 2002Tii calipers currently on my 914 have them on top...
(Soon to be LS430 Sumitomo monoblocks up front and 996 Brembo rears

)

raygreenwood · Post by **raygreenwood** » Mon Sep 14, 2009 6:06 am

Also...any competant machine shop with a drill press and a drill vise can simply add a bleeder hole on the other end as well.

Also...do you know what the piston diameter is? If its significantly larger than the stock one...those would indeed be a treat. I have cross drilled Zimmerman rotors on the front end of mine. The cross drilling helped quite a bit in hot Dallas traffic. having slightly larger pistons fro more clamping force woul help even more on otherwise stockish brakes.
I like the four pot calipers that Wally put on his...but thats more than I need. Your looks like the ticket if the pistons are signficantly larger. Ray

kps70 · Post by **kps70** » Mon Sep 14, 2009 8:33 am

Thanks for your comments guys. The calipers don't fit the other way around - your idea Ray of getting another bleed hole drilled is a good one. Next time they're off I'll get that done. I wonder if these BMW ATE calipers would fit a 412 the right way around?
Yes I put copper pipes on as these seem to be the standard replacements over here in the UK.
I must admit that I did not measure the caliper diameter but the pads are significantly larger than the standard 411 ones - I'd say a good 40% larger. The difference in braking is truly unbelievable but then again my old calipers were knackered!! I was actually brave enough to come home from work today the short way (down a steep hill)

ubercrap · Post by **ubercrap** » Mon Sep 14, 2009 8:43 am

raygreenwood wrote:Also...any competant machine shop with a drill press and a drill vise can simply add a bleeder hole on the other end as well.

Also...do you know what the piston diameter is? If its significantly larger than the stock one...those would indeed be a treat. I have cross drilled Zimmerman rotors on the front end of mine. The cross drilling helped quite a bit in hot Dallas traffic. having slightly larger pistons fro more clamping force woul help even more on otherwise stockish brakes.
I like the four pot calipers that Wally put on his...but thats more than I need. Your looks like the ticket if the pistons are signficantly larger. Ray

I think Wally has the E21 BMW calipers on front as well, but it was func412 that put the 4 piston volvo calipers on his race 412, IIRC.

raygreenwood · Post by **raygreenwood** » Mon Sep 14, 2009 12:24 pm

Thanks for the correction Uber!
Also....you should try these http://www.speedbleeder.com/
They freakin ROCK! Ray

kps70 · Post by **kps70** » Mon Sep 14, 2009 2:02 pm

They look good - available in the UK from
http://www.demon-tweeks.co.uk/
We pay more than you guys

wshawn · Post by **wshawn** » Tue Sep 15, 2009 7:00 am

Would these calipers fit later 412s?

The offset is differrent on the isn't it? If these don't fit which ones would?

More stopping power would be nice, even with new stock calpers, disc and pads on the front and new rear shoes etc the stopping leaves a little to be desired on mine...don't get me wrong, it does stop and the braking power is aceptable to the MoT man on his rolling road brake tester but...

raygreenwood · Post by **raygreenwood** » Tue Sep 15, 2009 7:56 am

Even without new calipers you can have literally awesome stopping power compared to stock. Here is what I did...and it easily cut about 30% off of stopping distance...no kidding!

(1) cross drilled front rotors
(2) 412 calipers....which you can slap right onto 411's as ling as you swap 412 steering knuckles on.
(3) Better friction material. Not race....but there are an even dozen friction codes. I can get you what I got so you can ask for them. I am using a mintex pad.
(4) mintex shoes on rear drums (I will be replacing with discs soon...but these works awesome)
(5) after market adjustable rear balance valve
(6) polish the master cylinder, caliper bores and compensation port valves with 2000 grit during rebuilding. No hone marks mean better seal and higher pressure.
(7) Teflon stainless brake lines on all four.

My pedal locks up hard at about 25mm of travel. A vast improvement over stock.

My next upgrade is moving to a bus master cylinder mounted in the trunk in the same position as power brakes. Ray

Post by **Piledriver** » Tue Sep 15, 2009 8:05 am

Assuming the late vs early 4XX setup is the same as the 914 (rotors are, IIRC) ...the BMW calipers need the mounting surface milled back ~ 1/8' on the late 914 setups to center on the rotor.
(AFAIK, both the 320i 2 piston and the 2002Tii 4 pots have the same offset)
YMMV.

raygreenwood · Post by **raygreenwood** » Thu Sep 17, 2009 10:49 am

On a related subject, how do you guys feel about the usage of teflon/stainless lines. I keep seeing dire warnings like that on Pelicans technical article. I put about 60K on a set and never had problems, though I was always quite careful not to kink or pinch them. I am also aware that only a few makers have teflon lines that are DOT complinat...like Earls. Ray

Post by **Piledriver** » Fri Sep 18, 2009 11:03 pm

raygreenwood wrote:On a related subject, how do you guys feel about the usage of teflon/stainless lines. I keep seeing dire warnings like that on Pelicans technical article. I put about 60K on a set and never had problems, though I was always quite careful not to kink or pinch them. I am also aware that only a few makers have teflon lines that are DOT complinat...like Earls. Ray

It Depends.

If you really want the ultimate hard pedal, and actually are one of those people who will inspect them once a month or so, they should last fine.

Most people are not that person, and 99.99% of folks should just run the std rubber lines, as there is NOTHING wrong with them if they are not 20 years old.

(BUT---If YOU have not personally replaced them, consider them to be factory installed and replace them on principle)

I have a DOT set purchased from pelican about 4 years ago, no issues, >50K highway miles.