74 power brakes going NUTS!!!

[Baghdad Dart]

My son has a friend that brought his car over today. Its a 74 360 4V with 727. It has power brakes and steering. It has a purple shaft cam I think he said it was a 282-278-474 or close to that. At first I thought he didnt have enough vacume, when I pulled the hose from the booster it had pleanty. I put it back on and saw the shaft in the back move forward like the brake was being steped on. The vacume actually pulls the brakes on some and even went so far that it made the brake lights come on. Any ideas??? I am stumped on this one.

 

[Baghdad Dart]

When he is driving it the brakes are actually on. When the booster is unhooked from the intake the brakes just work some what as normal without a booster. But when the vacume is put back onto the booster the brakes are on all the time, and some times the lights are on too. I hope that I explained this well.

Jeff

 

[6pk2goDemon]

Try replacing the brake booster check valve first......just a couple dollars new.

 

[Baghdad Dart]

Thats the kind of big fitting that is on the booster itself that the vacume hose attatches to?

 

[6pk2goDemon]

Yes....plastic piece w/ a nipple that the vacuum hose attaches to. If you have another Mopar around that you could borrow it from just to check .......

 

[Baghdad Dart]

Thanks, we will get to that tomorrow. Hope that its that easy.