1960 Pontiac Catalina V8 Two Wheel Drive Automatic 43650 miles
This Pontiac was converted by previous owner to power brakes from standard brakes. The power brake unit is Moraine. I've had the drums checked and they are fine. I've had the unit apart and saw no apparent problem. Everytime the brakes are applied, the car acts like the drums are out of round and brakes uneven. The system has new brake fluid and has been bled with no air found.
When changing from standard to power brakes the brake rods are different lengths. Also the master cylinders may be different. BUT- you should take all drums and check them for out of roundness, at least on a brake lathe It could be any drum on the car causing this. Also make sure they are adjusted correctly and sometimes the parking brake partially applied wiill cause this. You'll need to pull the back drums off and see if this is the case by manually looking at the parking brake mechanism.