Proportioning valve is shot!! need assistance :D

[xtrememopars]

So over the last few weeks I have been trouble shooting my brake system. I have come to the conclusion it is my proportioning valve. I replaced leaky booster along with the master cylinder, rear drum cylinders, bled the car till fluid is clear. took out the proportion valve and cleaned it throughly seemed like it was frozen and was very rusty cleaned all parts with evaporust and still have the following symtoms.

symtoms:
Brake light is stilla on. (emergency brake is fully disengaged)
The brakes slowly lock up on the car when driving to the point it does not move and I have to bleed the master cylinder to disengage the brakes.

anyways need a new prop valve and cant find it anywhere, any help or aftermarket suggestions that don't require modifying original brake lines??

[Bullitt-]

The symptom your experiencing  "brakes slowly lock up" makes me think the booster rod needs adjusted shorter.
 If the rod does not allow the MC to return completely pressure will build up.

[burdar]

I've heard that bad boosters can slowly apply pressure to the master as well.  Where did you get the new booster?  Did you have the original rebuilt or did you buy one from a parts store?  What year of car do you have?  Did you completely disassemble the prop valve and clean every piece...or did you just soak the valve without taking it appart?

[xtrememopars]

bought the booster and master new from autozone, I took the prop valve completely apart cleaned it. should have replaced O-rings but didn't but they seemed good thick with no cracks on them. about the adjusting rod we messed around with it but we got the right length i believe just going by the book.

[burdar]

Maybe try disconnecting the vacuum to the booster.  The pedal will be very hard so be careful.  Drive the car and see if the brakes still slowly apply.

[xtrememopars]

ill give it a shot if it still locks up what do you think it could be?still the prop valve?

[burdar]

What year is the car?

My prop valve wouldn't reliece pressure.  I had to pull up on the pin that sticks out the top in order to reliece the pressure.  Disassembling and cleaning the valve fixed the problem.

[xtrememopars]

73 challenger 5.6L

[Chryco Psycho]

I highly doubt it has anything to do with the prop valve , if bleeding down the brakes at the master is the only way to release them then the fluid will not return to the master reservoir .
 The light could be a sticky centering valve does it go off if you unplug the wire ?

[xtrememopars]

I highly doubt it has anything to do with the prop valve , if bleeding down the brakes at the master is the only way to release them then the fluid will not return to the master reservoir .
 The light could be a sticky centering valve does it go off if you unplug the wire ?

If I unplug the wire it still stays on,  I am going to shorten the rod on the booster and see if that does anything, also gonna unplug the booster and see if it still locks up. I don't know what else might be happening to cause this lock up.

[Chryco Psycho]

the brake warning light is a ground circuit , sso if the light is on the cricuit is grounded , unplugging the wire from the prop valve should turn the light off so it has to be grounded somewhere else , next place to look is the park brake , the prop valve is not the problem with the light .

[xtrememopars]

Nothing, retracted the adjusting rod a little still locks up  i think I am just gonna get someone to come and fix it,  like i said before only thing i have not replaced was the prop valve and I can't even find one 

what are symptoms of bad prop valve?

[Bullitt-]

Problems I've heard of with proportioning valves have to do with no pressure getting to the rear lines, I imagine there are others.
The way I see it if the valve was a restriction holding pressure, bleeding at the MC would not relieve pressure past the valve.

I was told once of a problem with rear brakes that were locking up being caused by a bad brake hose, the hose was letting fluid build up between the inner & outer lining "ballooning" which held pressure.
If this occurred on one of the front hoses I think it would effect the wheel it was closest to more than the opposite wheel.   

one source for valve, yours is probably md2272 http://www.classicindustries.com/mopar/parts/brakes/valves/proportioning-valve/

[dutch]

"retracted the adjusting rod a little still locks up"

did you measure it?   you don`t want to guess length there...     

[burdar]

I broke one of the valves inside mine and had to get a replacement.  A guy I buy a lot of parts from gave me 5 prop valves.  He had many more on the shelf.  I found one that easily came apart and pulled the part I needed out of it.  Then I returned the valves I didn't need.  If you want his contact info let me know.  He has a lot of them on the shelf.