Hi all; 1995 Chevy Montecarlo, 3.1. Brake and ABS light on. Did complete brake job, front rotors, calipers, pads, Rear drums, wheel cyls, shoes, and all new hardware. Lights still on. On troubleshooting, I find I get no brake fluid to either rear brake. Fluid comes out the 2 bleeders on the ABS unit, but does not come out the lines to the rear brakes when you crack them open at the ABS. Hopefully I don't need a new ABS unit. Is there a porportioning valve inside the ABS that needs centered? If so, how? Car runs beautiful, but has 168,000. What do you think?