I have a 52 F-1 with a brake problem I've never ran into before and hope someone on here might have an answer. The truck has an SBC (yes, I know it's a Chevy in a Ford but the motor was a freebie) with a Turbo 350 transmission and a Ford 9" differential. It has an F-100 brake pedal and master cylinder on it which is rebuilt, the brake lines are all new (3/16") along with all four wheel cylinders. The front brakes are stock F-1 and the rear are 11" drums. The problem seems to be when I'm in stop and go traffic the brake pedal gets harder to push making the truck harder to stop. This only happens after repeated stops and starts like stoplight to stoplight. If it sits for a short period of time it's fine again. Any ideas what might be causing it?

 

So you have hanging pedals from a F-100? It sounds like the pedal is preventing the pushrod from coming all the way out of the MC, releasing pressure and taking a fresh gulp of fluid. Should be definite clearance between end of pushrod and piston in MC with brakes released.

If you meant you have the stock '52 setup for M/C, same comment applies.

 

Almost sounds like heat related brake fade. Drum brakes will do that if you're running hard light to light.

 

I'd say by your post that it's heat related also. brakes work by converting motion energy to heat energy so the more heat buildup the drums get the less effective they become. This would also explain why it is better after the truck had cooled slightly. If it's a problem you run into a lot you may look for a disc brake conversion.

 

Thank you everyone for your input, now it gives me someplace to start. I think Ross may have the answer as I have very little free play in the pedal before the rod hits the plunger in the master cylinder so after repeated stops the brakes don't fully release and heat up causing them to fade. Also could be the spring in the master cylinder could be weak and not allowing it to return fast enough? I'm not on the gas hard between stop lights as I know I need to leave enough room between me and the cars in front of me for safe stopping distance given that I have just four wheel drum brakes. What's weird is I have another 52 F-1 which is basically stock with a flathead V-8, three on the tree and now a Ford 9" with 3:50 gears and I've never had a problem with the brakes on it. Just for your FYI the brake pedal master cylinder combo is out of an 53 to 56 F-100 with the bracket bolted to the frame.