I recentlly rebilt my whole brake system all new parts on a 1973 non power brakes car, They work great but the rear brakes are grabbing enough to stop the car if rolling on its own. I feel that and know the the brakes are on slightly on in the rear cuz my breaks smoke after a 4 mlle ride.... Any Ideas on why.........

 

Well that's a bit annoying. Some things too check, the free play on the foot pedal rod to the master cylinder, there should be a little slack there, not tight. (the slack is easy to feel if you use your hand on the pedal) You might consider checking the proportioning valve, making sure its not sticking, (you might need to remove and clean) Then check the park brake and adjust if necessary, check the parking brake cable to make sure it's releasing and not gummed up and sticking, clean and lube if necessary. there is also a very small hole in the bottom of the master cylinder, make sure that's open with no brakes applied. There are 2 One in the front reservoir and one in the rear, you should see fluid returning to reservoir when brakes are released, If it's not open it keeps pressure on the brakes, and increases when fluid warms up.

 

So did you replace the rubber lines in this brake job? If not, start there. They deteriorate from the inside out.

 

Good call on checking the rubber brake lines. I had one fail with the inner portion coming loose and it actually acted as a check valve on the brakes were applied because it wouldn't let the pressure off. If you didn't replace them, I would recommend using the braided stainless lines because they don't expand with pressure which prevents a soft pedal.

Good call on checking the parking brake cable system also. If the parking brake hasn't been used then it does get applied, years of water and salt cause it to bind up inside the cable housing. The rubber boot on the end of the housing apparently does not completely prevent water from getting inside the cable housing. Also on a car this old, the rubber boot may not even be there anymore.