A guy down the road from me just built an old 51 Chevy... I was looking at it and he has no proportioning valve at all. He added new power disk brakes to the front, kept the drums in the rear and says the brakes work, but won't lock up under a panic stop. With no valve, shouldn't the rear lock up all the time? I talked him into getting an adj. prop. valve, but I am wondering why they work at all? He said the brakes slow the car down, but don't feel like they "clamp" hard enough, is that related to no valve or improper bleeding? They supposedly don't need to be pumped while driving and he said they were bled 3 times.....

 

Some MC's come with the valving inside them. What kind of master cylinder is he using?

 

Looks to be a stock older GM unit. It is cast iron...

Jason