Just shooting from the hip but if your truck is like my '50 COE, the end of the bolt is peened over the disc. My truck has Huck brakes which should be the same as yours and my adjusters are OK so far. Just in case I have problems in the future, I was able to obtain NOS replacement bolts and discs and I had the same question. Looking at the adjusters on the truck, they are peened on. I think it would be difficult to do this on the truck and might require removal of the backing plate so you can put the assembly in a press.
Kent
