Brake bleeding w/ ABS?
 

Ok, now the car goes great, but alas, my brakes are messed. 85 300sd. Originally had ABS, someone took out computer and apparently one relay. Brakes worked fine for a while. Replaced wheel bearing Sat. night. Took off caliper and replaced (hung from coathanger). Left front caliper then started sticking/dragging. Heated up the rotor on drive home. Researched and replaced rubber hose, thinking inside was restricted. Now cannot get brakes to bleed. Bled a little at ABS servo, but nothing at caliper. Car is immobile (again)..need suggestions.
THX

brake bleeding with abs is the same as regular brakes as long as the abs control unit hasnt been touched. the only time you need to worry about it is when you are dealing electronically controlled brakes such as the SBC system of mercedes and lates vehicles such as GM using it and others. its always good to refer to the service manual before proceding.

Whenever I bleed the brakes on my TDI I re-bleed the ABS controller so I'm sure its not full of old fluid. The old Bosch ABS on our benzes has no extra bleeding procedure however, so doing a normal brake bleed gets all the fluid.

-Jason

true except the for models with ASR which have a slighly different procedure.

Yes, but no olde diesel benz has ASR. If they have traction control it's ASD, which has its own hydro. circuit.

-J

update
 

OK, I think I found culprit. If I am seeing correctly, the ABS unit on the fender well has basically two components, upper and lower. Upper is for front, and lower is for rear brakes? If this holds, the line coming in the front top is the supply from the master and the two out the upper rear are to the front wheel calipers. By loosening the front upper, I do get pressure bleed. The back two, however are basically dribbling..ie no pressure passes thru. If this is a correct assumption, then I believe that my ABS unit is seized or bad?? Still no bleed pressure at either front wheel. Any experiences out there?

I own this car now and decided the abs was making it impossible to bleed the brakes properly and was causing the left front to drag. I bypased the ABS unit with brake lines and it seems to be working now. In the process we managed to bung up the lf caliper so I had to spring for a rebuilt unit on that wheel.