The Stovebolt Site Forums The Shop Area Driveline master cylinder

So my next issue is bleeding the brakes in the '37 1/2 ton.
I replaced every single part in the brake system including the master cylinder, lines,
wheel cylinders etc. First pump of the pedal goes right to the floor. A couple pumps more and it's hard as a rock so there's
air somewhere. I've been advised to bench bleed the master so I've pulled that and have it in a vise. No info in the shop
manual on bleeding it.
The brake line comes out of the inboard side of the master cylinder and the brake light switch threads
into the rear of it. So what's the procedure for bleeding the master cylinder?
Thanks everyone.

Hy '37 barn find, To bench bleed a master cylinder loop a short piece of steel brake line from the discharge port of the master back to the reservoir, submerge the end of the line in the reservoir fluid so you can check for bubbles. Now with whatever tool you have that is appropriate push the master cylinder piston in and let it return all the way to its at rest position do this a few times until all the bubbles disappear from the fluid in the master cylinder reservoir. Once that happens your master cylinder is successfully bled. One other thought I had is, did you adjust your brake shoes up before you bled your system? Hope this helps.

Thanks for the reply.
I have the shoes adjusted so I should be good there. Should I remove and try to fill the brake switch or put a brake line there and pump as well?

Hy '37 barn find, If your brake piping system is still as it was designed by the factory, everything downstream of the master cylinder should bleed correctly.