One Cool Custom Classic

Brakes not Braking

Brakes
Dad is having trouble with the brakes on the car. You can stand on the brakes, and still not able to stop the car very easily. Dad has talked with several different people about the issues, and everyone has their own thoughts as to what might be causing the issue. We have changed the pads all the way around, put on a new master cylinder. We have changed the rear calipers and put in a new and bigger break booster. We have checked the vacuum at the booster and that appears to be sufficient. We have bled the brakes numerous times to no avail. Some have suggested that we go get the brakes bled professionally or even to get a bigger bored master cylinder. The only thing we have not changed is the proportioning valve. The valve we have does not have any adjustment, it was supposed to be setup for the car, so it should work correctly. At this point we are at a loss.