Hey guys i will start from the begining and see if anyone can help me, and to those who have helped so far, thank you so much!! i greatly appreciate it! ok, i got a near rear end for my car. my car was originally a drum brake open rear. Now i have a 9 bolt disc brake posi rear. I changed the proportional valve to the disc brake valve. i bled the lines and everything and i made sure i didnt get any air in the master cylinder. After i bled the lines, only my front brakes were working and i had no braking power what so ever to the rear, and my warning light came on. I learned that this could happen when changning prop. valves and that i would have to bleed the front lines again to reset the switch in the master cylinder which would turn the brake warning light off and give me power to the back. I did this and the light did go off and i did get braking power to the rear until i pushed down on the pedal again. This made the light come back on and once again i had no back brakes. so i repeated the procedure and the exact same thing happend. i didnt know what to do so i just figured maybe i would clean the little pressure switch on top of my prop valve and as soon as i pulled it off, the light went off and stayed off, and i have a little bit of braking power to the back, but not very much at all. *edit* i just took the car for a ride, and i could feel the back brakes a little but the light came back on. and i noticed that my water temperature gauge and my battery power gauge both did not work, so when i pulled over and plugged the pressure switch back in my two gauges worked again. im so conufused with my car. does anyone have any idea what is going on?? Thanks

-Ian

 

Master cylinder may be shot.