Need help with non-working brakes.

[GLHNSLHT2]

So bought a 88 Lancer Shelby for a winter beater. Pedal goes all the way to the stop, left rear and right front wheels can still be spun by hand. Put new wheel cylinders and shoes on the rear yesterday, brake fluid is nice and clean with no bubbles. Do I have to replace the Prop valve? MC? All brakes seem to be bleeding fine but those 2 just don't work. Pedal goes to the stop no matter what. Need some guidance/advice/help. This was supposed to save my Shelby Lancer from winter driving and the snow is gone for the rest of the year now, it all went back east. If I can't get the brakes to work on this rusty canadian car I'll part it and scrap the body.

[85boostbox]

Prop valve is my bet.

[4 l-bodies]

Jay,
My bet is master cylinder. My experience is when you have one rear that locks up earlier than other it is failed proportioning valve. My understanding is the proportioning valve controls the split point and is a separate left and right rear wheel circuit. Really should not be controlling pressure of left front caliper. You may have lost the e-clip internally in the master cylinder. Also check for brake fluid in booster. It sounds like primary port in MC is not functioning correctly. Regardless I would change out the master cylinder first as it is easier and cheaper to change out.
Todd

[GLHNSLHT2]

I've got a Master and prop valve from a Spirit R/T I was thinking of throwing in. I don't have any drum brake prop valves except the one on the car.

[cordes]

My money is on the MC. If it were good you should have pressure at either corner IMO.

[onerippinturbo2]

if the prop valve is tripped it will stop the flow of fliud to the other side of the circuit, i would try to re center the prop valve by opening up one of the good wheels and pushing the pedal to the floor with the bleeder open and see if you feel or hear a pop from the valve re centering.

[thedon809]

I would put my money on the master.

[black86glhs]

Nevermind. It could be either one causing the issue.

[onerippinturbo2]

2 lines go into prop valve, 4 come out, how in the world would the mc be able to direct fliud between the lf and rr through 1 line and then the prop valve??, if that was the case, the master would need more then 2 lines out of it

[black86glhs]

2 lines go into prop valve, 4 come out, how in the world would the mc be able to direct fliud between the lf and rr through 1 line and then the prop valve??, if that was the case, the master would need more then 2 lines out of itAfter looking at it again, it could be either one bad. The MC provides the pressure, but the prop valve splits it to the front and rear.
I stand corrected. I thought it was a 4 line MC.

[GLHNSLHT2]

Changed the MC and prop valve with one out of a Spirit R/T since it's all I had lying around. All the brakes work. Pads need to be broken in some more and probably re-bled again but at least there's some confidence in stopping now.

Also figured out there's a common part # on the 11" 4 wheel disc prop valves vs just a tag color. I'll post the info somewhere else tomorrow since I forgot to put the #'s in my phone.