new stock brake system, big problem

[AZMoparboy]

Hi again Guys,

I've rebuilt this 1973 charger brake system almost completely. The boost is the only thing that is original. The rear brakes are working I think just fine. At this moment I can not move the car because the front brakes are locking up and the fluid pressure is not releasing. To release the pressure from the front calipers I'm having to crack a brake line from the proportion metering valve. I've check the push rod, I even removed the MC from the boost to see it was holding it, but no, still holding pressure. I then cracked the MC front line to the proportion metering valve, no, still holding pressure. I then go to the proportion metering valve front line connections. That relieved the pressure from the front calipers. I think I have a metering valve that is not right. This is a valve that is from inline tubing. It looks just like the original valve and has all the connections as the original. I've bled the lines and brakes, feel very solid. I've even bled the valve out of the front line connections, but every time I see if it will work, it just locks up the front and holds pressure and I can see that the valve stem at the front of the valve is out and very tight, but once I releave the pressure by cracking the front line the valve stem then is loss and calipers have no drag or are locked up:shruggy: This is a new valve, could it have a malfunction or is this a simple valve the can not miss up, or did I do something Wong on installation of the valve, or the bleeding of the brake lines

Hope someone can shed some light on this problem
Steve Porter

[b5blue]

Did you reset the little imbalance thingy pin on the prop block? Maybe it's pushed one way?  Is your brake warning light on?

[AZMoparboy]

Thanks B5blue,

I gave in-line tube a call this morning and they said to try to reset it also. My helper was not a home today, so I'll have to wait till I have a helper to pump the brake peddle. I hope this works, I'm doing a lot of the car stuff for the very first time ever, its all a learning thing, will keep you informed.

Steve Porter

[b5blue]

Good luck I'm sure you will get it right...if you get pissed just back away slowly...there are some chevy and ford cars out there with my knuckles dented in them! 

[AZMoparboy]

Hi Guys,

Update, Yesterday I fiddled with the proportional valve a lot more. I intentionally setting the shuttle valve within the proportional valve off so as to get a warning light on the dash. I then reset the shuttle valve so that it would go off. I did this a few times just to know for myself that I was finding the correct position and I was getting the no light condition. I thought I had it, so I started the car and applied the brakes, but no, it locked up the calipers again

So I broke down and called a master mechanic of 30 years with mopar experience, told him all that I had done. He then said I had already diagnosed the problem, he said that, that valve should never hold pressure as it is doing

This morning I got on the phone with inling tube Inc. They said to send it in  and they would put it on their tester and check it out.

The proportional valve is in the mail and I'll keep you all informed  :popcrn:as to what is going on with this valve, it should not be this hard to install a new valve in a new system and it work the right way.

Steve

[b5blue]

Years ago ....when I worked on English cars there was a problem with the inside of flexible brake lines swelling up inside and acting up like you describe but both fronts at the same time no, both rears could from the flex to the axle.Your sure there is no residual brake valve in your master cylinder right? I think you found the problem  If you have the old one I'd clean it up and try it, if it works just get a refund and go buy a steak and some booze!