[mopar-man 3000]

well i notice while driving to work that my breaks went out the door so i checked the master and the rear resivor was bone dry so i looked around and no leaks that i could see but a liitle at the rear wheel but not a big leak so i fixed that problem
bleed the whole system master on down and still no breaks now the pedal is weid it's mush untill almost down and then it gets real hard and the break light in the dash turn on pumping the breaks has no effect
it almost seems like the back break are not getting enough fulid no the only thing on my break system that is not new is the proporiton valve thats it can this go bad they dont sell them at the auto store because they like never go out is what im told also i have a 70's style breake system with drums all around also would a porp. valve from and 80's truck with disk front work ?
thank in advanced
richard

 

[Chump]

Are you still seeing the fluid go down in the master cylinder? Are the rubber hoses in good shape?

 

[BrianT]

Probably the wheel cylinder is what is making the leak . u won't know it's there unless u pull the drum off and check the rubber on cylinder . they are chepa to replace but a pain the ass to do drums and might as well do the brakes while u got it apart anyhow .

 

[Guest]

The rear resevoir should be plumbed to your front brakes. It should be larger because the 1980 came with disc brakes. Did you install the earlier drum brake axles and retain the 1980 setup for discs? Somebody correct me if I'm wrong, but a drum system does not require a proportioning valve?

 

[mopar-man 3000]

Are you still seeing the fluid go down in the master cylinder? Are the rubber hoses in good shape?

well il check my ruber hoses tomarrow they are like 30 years old and the fulid im not to sure ive only drivin it about 3 mile since the bleeding

 

[mopar-man 3000]

The rear resevoir should be plumbed to your front brakes. It should be larger because the 1980 came with disc brakes. Did you install the earlier drum brake axles and retain the 1980 setup for discs? Somebody correct me if I'm wrong, but a drum system does not require a proportioning valve?

no i put a 80's cab on a 74 drivetrain which had all drums and proportioning valve(id assume)
well im going to do some more looking around tomarrow i have a helper for the bleeding instead of one of those 1 man deals
could the porp valve be stuck or something

 

[Chump]

I have never seen a prop. valve actually go bad. The problem I have seen is that some people will not get the system bled correctly and have problems with the valve not getting centered properly. This causes some wierd pedal problems and the light on the dash to come on and off randomly. I would check to make sure you havnt blown a wheel cylinder somewhere or maybe have a pinhole leak in a metal/rubber brakeline. The prop valve is usually located almost straight down below the master cylinder and is mounted on the frame. I would assume that you bled the rear right, then the rear left, then the front right and then the front left...in that order? Had to ask that

 

[440Ramcharger]

My suggestion is top off the master cylinder, leave the caps for the master cylinder off, open the bleed valves on one axle at a time, let the system do a gravity feed and force the trapped air out of the lines and wheel cylinders. This can be sped up if you have a Mighty Vac tool.

 

[mopar-man 3000]

well i figured it out its the only old wheel cylinder on the beast it has a small leak in it thats why i dont see fulid leaking out of the drum so i bet you guys can guess what im doing tomarrow thanks for the help go mopar
Richard