ABS Unit Clogged

[riseosiris]

On a 91 535im, with the ATE Master Cylinder and Bosch ABS unit, the ABS unit appears to be clogged for just the Passenger Rear brake. I have trouble shot all the lines coming out of the top of the ABS by individually disconnecting from the top and pumping the brakes. All have fluid coming out except for the one which leads to the right rear. Given the state of the master cylinder (lots of nastiness from going too long without a flush), I have to assume one of those little bits broke loose and lodged into the ABS unit (both lines leading from the master cylinder run free as well).
So, is this something I can take apart and clean, or are we talking a replacement unit? Naturally the Bentley is no help.
Thanks!
-Lloyd

[nmp411]

I apologize for not having an answer for your question, but if you do end up needing a replacement unit I have one for sale. PM if you figure out if you need one, and good luck.