Front disc brakes locking up, 72 Duster

oldirish said
Sounds like a good place to try next.

View attachment 1716348292

Oohhh. So that’s a brand new booster and GM style master cylinder. So some online kit deal then?

Is this a brand new install? As in, did this car have working disk brakes before and you just added the booster and master cylinder? Or did this car not have working disk brakes before?

oldirish said
The brake pedal isn't tight, there some loose travel at the top.

That’s a problem.

oldirish said
Image of proportioning valve

View attachment 1716348298

Looks like a 73+ style factory combination valve. With some definitely not factory brake lines.