1952 Easamatic brakes

Posted by Thunderbolt On 2015/3/19 9:41:06

I'm tying to figure out why the brake pedal gets mushy in the '52 300. It only happens when the engine is good and hot and I've been driving for 20 or 30 minutes. When I try to stop it usually goes to the floor and locks on the toeboard, if not it requires a careful touch. Also when on an incline the pedal slowly creeps down.

All the wheel cylinders and master have been rebuilt. The master was also rebuilt 6 years ago along with the treadle vac. I've read about the compensator valve and diagpragm or cylinder wall air leaks. The mechanic says it's all working as expected and the fluid is full and clean so I had few clues. I figured rebuild the treadle vac again and reline the shoes. Then it occurred to me that the heat of the brakes and the heat of the engine are overheating the fluid. I'm thinking about switching the brake fluid to ATE Super Blue racing fluid and making a heat shield for the master. Any thoughts on how effective that may be?

-John