Brake bleeding problem

[broke30]

Hey all,
Well I have been having a problem with my 1990 325i in which I removed the abs. It came time to bleeding brakes and the rears bled just fine and the pedal went to the floor as it should when the bleed screw was open. However, when pumping the brakes with the bleed screws closed and also when the FRONT bleed screws are open, the pedal doesn't go to the floor and hits a sort-of barrier. It sounds like metal on metal, not a pressurizing sound... I'm up for any suggestions! Thanks in advance
Max

[jlevie]

I should have asked in your question on another forum, but didn't think of it then.

Did this problem surface just after the ABS delete and were the brakes working properly before the re-plumb? If so I'd suspect a plumbing error in deleting the ABS. If not I'd suspect the master cylinder.

[broke30]

The plumbing should be all fine, I checked for kinks or breaks in the lines and nothing. Would a master cylinder from an early model work because I have an extra one laying around...
Max

[Massive Lee]

Hi broke30

I suspect that the grinding noise is some interference in the mechanism in the footwell.
We sometimes associate certain problems to certain actions (rear bled fine, but got problems with the front). Don't worry. Do the front too and see what happens.

BTW Rear and front brakes are not hydraulically independent. They are part of the same system. If one line is not bled properly, the whole system will suffer. Do the bleeding and let us know how it went. When opening the hydraulic system to your extent, don't be surprised to waste a full litter of fluid before you reach perfection. Especially if the MC is full of air. I particularly like working with a pressure bleeder and somebdoy to press the brakes. It kinda help getting rid of any air bubble.

[broke30]

Massive Lee,
Thanks for your input. I checked and rechecked the pedal assembly and actually had put in another set of pedals and same thing. Well I got around to installing the other master cylinder I had from the early model and the brakes all bled fine and the system seems to be working as it should. I'll keep everyone updated if anything else happens!
Max