Technical Drum brake diagnosis

I own a 1951 chevy styleline deluxe. I have an issue with my brake pedal getting harder after 10 miles of driving. when the car is parked and i first start it, the brake oedal has about half an inch of ttavel before its hard. as i drive the vehicle it becomes harder, to the point that it has no travel at all. I usually pump it a few times just to soften the pedal. At this point I believe that the master cylinder maybe at fault or could be overfilled. The master cylinder is rebuilt, the brake fluid is dot4, new brake shoes and wheel culinders replaced, new hard lines snd soft lines replaced. Also noticed that the front wheels start to drag over time.

 

Make sure that the pushrod that operates the master cylinder has a little play in it.

 

Brake pedal becomes hard after driving , applying brakes ( 10 to 20 times )or just driving ?
If after applying brakes several times, sound like fluid is not being returned to the master cylinder

 

My 40 ford did the same thing. I adjusted my pushrod to have more free play and it has been fine since then. I ALSO use dot 4.

 

Make sure you have a good pedal return spring that fully returns the pedal every time, then adjust for about 1/16" push rod free play.

 

Make sure that your rubber hoses are new. When they degrade, the inside comes apart and acts as a one way valve.

 

Ill have to figure out how to adjust the pushrod.

 

Yes after driving and applying the brakes over time. the pedal becomes harder, and the front wheels start to drag. yes it seems like the brale fluid is not returning. I have to pump the brakes 3 or 4 times to soften the pedal. The brake fluid is filled up to the top. THat could be a cause.

 

All replaced parts are new

 

Ill have to look into it. not sure how to adjust it. I havent noticed any issues with the return spring.

 

Not just old hoses will do that. I had a new hose do that to me on a F100. I completely put on new hardware, shoes, hoses, master cylinder, proportioning valve and wheel cylinders everything. Bad p***enger front hose out of the box. Would pull left when I touched the brakes. Bad lining in the hose that made a flap under pressure.

 

Problem solved, bad master cylinder, master cylinder was not rebuilt properly, piston came apart. replaced the master cylinder, going to get the old master cylinder sleeved and rebuilt properly. Thank you for all the help.