1941 Plymouth P12 brakes locked up

[CHS]

when you did all this brake work did you replace the front flex hose that goes to the wheel cylinder? Over time they deteriorate on the inside. Collapse, restricting the flow of brake fluid.

[Lindsay McConnell]

First thing that came to my mind is a burr in that wheel cylinder. I had a similar problem 20 years ago when WhitePost Restorations rebuilt all my cylinders and master. They sent them out the door at that time with only air pressure as a test. Once fluid was used the problem surfaced.... Good luck!

[Rkatk]

Help, I am in Plymouth Brake Hell.
The drivers front wheel in my 41 P12 sedan is locked up tight.
I have put in new wheel cylinders all around.
Adjusted and centered up all of the brake shoes.
Removed the master cylinder, rebuilt it and cleared the pressure relief hole.
I checked the line pressure coming out of the master cylinder and with the piston depressed as much as I could I get 30psi and when the piston is released it holds a steady 10psi which is exactly what the residual pressure valve is supposed to hold.
  All of the other wheels, passenger front and both rears, will brake and release just as they should, only the drivers front locks up.
  Any thoughts or useful suggestions?