Replacing parking brake cams and bushings. Are the bushing pressed in the backing plates?
In a word: yes. And then you may have to ream the bushing to get it the proper size to fit the brake cam shaft.
I might add that you will want to support the backing plate area as THEY will BEND !!!
If you have a Ruckstell made by Hall-Scott, there will be no bushing to replace. Not until Eaton bought them out, did they start using Ford backing plates.
The Ebay Ruckstell I'm rebuilding has a pretty wallowed out brake cam hole on the Ruckstell side, is there any harm in drilling the hole larger to take a Ford bushing?
You do have to be very careful "drilling out that hole" because the hole wears crooked and to one side. A drill will try to follow the new center and you will wind up with an off-center brake cam. That may or may not cause troubles. Because of the brake rod pressure, the hole tends to wear forward, gravity tends to move it down. The new cam might hit the brake drum if the hole moves that way. The shoes also may not center properly with the brake drum. Some of that can be adjusted for with careful fitting of the brakes.
What I have done in the past, and probably will again, is use a big sharp rat-tail file and enlarge the hole on the non-worn side back near center. It is not difficult to approximate the amount and area that needs to be removed, and mark it with a fine felt tip marker. Filing straight is a bit more difficult, but doable. Actually, it is not all that difficult to do, the backing plate is soft iron and cuts quickly with a sharp file.
Once the hole is moved back to proper center, if you have the drill to do so, you can drill or ream the hole to proper size for the bushing.
Ruckstells are not the only ones to not use a bushing there. I don't know if they were late Ford housings or after-market replacements. But I have seen several common standard type housings with no bushings. Just a hole drilled in the casting. And usually a one rivet brake arm. Although I repaired a couple of them in the past, and have about 20 housings in various conditions in my piles, None of the ones I currently have are that way.
Drive carefully, and enjoy, W2
Thanks for the tip, Wayne, the wear on mine is exactly like you described. I will file first, then drill or ream.