R90s brake calipers

[Scotty54]

Question on brake calipers on a 1976 R90s. Are the calipers specific to left or right sides? I made the assumption (I know what that means) that the calipers were not exclusive to left or right after rebuilding them. I’m having some bleeding issues so need verification on my assumption.
Thanks
Scott

[Workinman]

Make sure the bleeders are ABOVE the brake lines. If you switch sides the bleeders will be below the brake lines and you will never get it bled.

[Scotty54]

Can the bleeders and brake lines positions be swapped to maintain that configuration? I’m assuming they both connect to the same chamber?

[Workinman]

I can’t say for sure, but I’m guessing they are different. I’ve never tried to switch them on a BMW.
I have, though, installed calipers backwards on cars before, and then spent two or three days trying to figure out why they won’t bleed.

[johnlacko]

Scott, the calipers are the same on each side, so no left or right. Only one part number. Are you having trouble getting a firm lever? Most of the time it’s not a difficult job to bleed the brakes, but every now and then I’ve had one that seems to take three times longer to do for some reason. But I have not had one yet that didn’t work in the end.

[Scotty54]

Thanks John.
That is what I suspected, but now I’ll sleep better. I am having problems with the bleed. I’m going to use Indians suggestion from a while ago and push from the calipers up.

Scott

[Workinman]

If the calipers are the same you will still need to switch the lines and bleeders so that the bleeders are on top. If the bleeders are below the lines they will not bleed. I don’t know why, as I’m not that smart, but I know they won’t bleed if the bleeders are below the lines.

[Tinkertimejeff]

I am not that smart either, believe me! Butt, air is lighter than the brake fluid, it will always seek out the highest point in its environment unless there is zero gravity. The bleeder should always be the highest point on the caliper, you can push the air down into the caliper BUTT! if the bleeder is not the high point it will stay put in the caliper at the high point. Basic physics at work!

[Scotty54]

Thanks. I actually did move the bleeder and brake line so the bleeder is on top. It seemed logical to make the new caliper match the other side. I’ll update when I’ve finished.

Scott