First time adjusting Pullman heavyweight rigging. It’s simple and straightforward. Here’s the bugaboo: the car was converted from UC to ABDX. It now has a 10” cylinder so the pin hole in the yoke of the push rod is smaller in diameter than the hole in the cylinder lever. This makes almost an extra 1/2” total slop that I’d like to take out. Is it OK to make a bushing of sorts for the cylinder lever pin hole to take out that slack? Or is it possible to change out the push rod to one with the proper pin hole size? My concern is twofold - additional wear on the pin and lever hole due to the mismatch in size and removing unnecessary additional slack in that end of the rigging.

OK, I'll bite. Make a bushing, but tack it in so it doesn't fall out.

So, I will bite. How do you go from a 16” or 18” brake cylinder to a 10” cylinder and get an appropriate brake ratio?

That is a question I have no answer for. It apparently passed muster with a couple Class 1s and a short line, though. A guess: looks like it has HF shoes. Dunno.

[Edit] I deleted a dumb comment - didn’t have enough caffeine. I don’t know how they got by with a smaller cylinder. I understand that inspectors stood there and watched it work before they approved it to move. The car also weighs less than when built so maybe that’s a factor. Good question.

High friction brake shoes produce the same braking effect with 1/2 the pressure, so the smaller cylinder is appropriate. If it isn't practical to replace or bush the brake cylinder, then the same effect can be achieved by changing the ratio of foundation brake rigging levers.

I agree with the plan of bushing the lever hole. The reduced thrust of the smaller cylinder will make the smaller pin appropriate.

Thanks, Kelly. I was thinking that the HF comp shoes was the deal, and the owner’s mechanic also confirmed that it was OK.

At a quick look, the only slack adjustment holes are two on each side of the trucks to get things sort of close. It has a slack adjuster like the original that holds the dead lever so that’s the finer tuning. The rigging is simple but elegant.

I’ll see what we can come up with for a bushing. That 1/2” +/- makes a noticeable (to me) difference across the lever to the top rods.

Standard pin hole size for the cylinder push rods and dead (floating) lever attachment up to and including 12" was 1-1/8". Standard pins are 1/32" undersized. So a 1-3/32" pin connecting the push rod to the live lever. I don't have data for 18" cylinder handy at the moment. For 14 and 16, the hole size was nominal 1-1/4 and the pin is 1-7/32

Bushings in the cylinder levers are press fit and are made of hardened steel. You can get bushings from General Bearing. Regular style "P" drill bushings will also work but they tend to be chamfered on the OD at one end only, and on the ID at the opposite end, because they are intended for guiding drills through jigs.

Your lever is probably using a bushing with a nominal 1-1/4 ID and 1-3/4 OD. Verify this dimension, then go and order new bushings with the same OD, but stepping down to a 1-1/8 ID. Take the cylinder levers down, marking them carefully as to which end is which. Bring them to a press and press out one old bushing on each lever and press in new bushings. If you are using drill bushings, just watch carefully and put the OD chamfered end into the lever first so the bushing presses in squarely. Just change the bushing on each lever where it connects to the cylinder. The other bushings should be correctly sized already to the body rigging.

I don't recommend trying to use a separate "adapter" bushing to sleeve out the pin.

I may have a pushrod and pin with the correct sized hole. I’ll see if a swap is possible. That certainly would be the quickest.

Thanks to everyone that responded on the cylinder size with the HF comp shoes. I was getting ready to dust off the calculator app and try to figure it myself and yinz guys saved me some head scratching’.