oldcrusty528

I'm trying to get a basket case 2008 528i back on the road. It's sat at least 3 years. Only has 97k miles. After getting it running and driving the brake pedal felt odd. I went to bleed the brakes and the right rear wouldn't bleed. No fluid would push through. All of the other brakes bled. The pedal is hard, it doesn't go to the floor. I drove around and verified the rotors were hot except for the right rear. I disconnected the line from the ABS unit and blew air. I could see fluid flow, so it's not a line issue. There are no CEL/ABS codes in the computer. The car drives just fine. The only codes are seat belt tensioners and TPMS (working on fixing them). Why can't I bleed that one line? Could it be the electronic ABS module?

habbyguy

The rear lines are subject to rust just ahead of the left rear tire (there's a gap in the undercar shields that allows road gunk to assault the metal lines there - both rear wheel lines are together there). But if you're pushing fluid and air from the ABS unit connection to the rear caliper connection, it sure sounds like the line is good, which (IMHO, don't quote me) sure sounds like a problem in the ABS unit. I believe there is an ABS test utility in some advanced two-way scanners, and of course the laptop-based utilities like INPA / ISTA. I'm guessing that might clear a clogged passageway / valve / port, or at least confirm that the ABS unit is bad.

oldcrusty528

The car has no rust, can't blame it on the lines. I swapped an ABS block with original electronics and I got the right rear to bleed, but then the front left wouldn't. Guessing I switched the lines, I attempted to switch them back and cross threaded the right rear. I suppose next step is to swap back to original ABS block with new electronics but I need a coding utility to do that.

habbyguy

Hopefully the line connectors are still OK, Also, I think there's some possibility that the original issue was in that (soon to be reinstalled) block - I'd make 100.000% sure that all the passages are clear before going to the trouble of rebuilding the ABS unit Frankenstein style.