The Stovebolt Site Forums The Shop Area Driveline master cylinder alignment issues

Just bought a new master cylinder for my 58 half ton and ran into problems inserting the alignment pin that attaches the brake pedal to the master cylinder. The pin inserts into the first ear of the master cylinder and into and thru the brake pedal assembly but will not pass thru the backside ear of the master cylinder. I did some honing on the backside and it will go now with some tapping with a hammer but the swing action of the brake pedal is tight not allowing the pedal to make a complete release. It sticks just enough to keep the brake light switch engaged. Are the new cylinders that tight or is the line bore on this one off just a bit? Maybe the repos are made for tapered pins. Anyone else had this problem?

The pin on my '55 slides in and out with just a push of a finger. I rebuilt the original cylinder, don't know if the '58 has the same one? Yours sounds as if it is not right....

I rebuilt mine twice and it works fine for a while then starts to build up pressure and finally locks up the brakes. had tons of rust inside it when I bought the truck. This is a cylinder I bought thru Amazon made by Raybestos and I think I will have to ream the ears a bit. On the original master cylinder the pin inserted just like yours, with the push of a finger.

took everything back off and checked the hole alignment with a piece of cold rolled 7/8 inch shaft stock and found the holes in the master cylinder to be about 1/16th of an inch off. Somehow it moved while drilling of was not set up correct. I used a 7/8 inch metal hole saw to correct the misalignment. Now the pin slides in just pushing with my finger.

Had one that would lock up the brakes as it warmed up, on a 64 Chevy 1/2ton, along time ago. I was on the freeway on the way to work early in the morning, and the truck started to slow down and gradually came to a stop. Sat for a while, and then was able to get off the freeway, then it came to a stop again. Took a while to figure out what was up. Put a new master cylinder in on the side of the road and got to work late. The piston had crumbled slightly and the debris would inhibit the movement of the piston. You might have some dirt/rust in the bore?