Lip on new Brake Plate Won't Fit Groove in Hub

Just a quick update.  I ended up going the "grinding down the thickness of the flange" route.  I worked on both brake plates until they fit the hubs with a reasonable amount of clearance and proceeded to install one on the axle and slip on the hub with newly packed bearing & seal.  I figured that there was going to need to be some more grinding in select spots, so it was no surprise to me when the hub was bound tight after tightening & loosening the castle nut.  So I proceeded to remove the hub by pulling it toward me and giving it a good nudge to try to get it to rotate...and that's when I did get a surprise.

You see the flange on the new brake plate doesn't go all the way around the perimeter like the old brake plate.  Instead there are two gaps as you see below:



And the surprise that I found?  Did you know that you can see stars in broad daylight if your fingertip happens to be poking through one of those openings at the instant that a heavy steel (iron?) hub decides to break loose and turn around the spindle?  And it's a pretty good feeling when you realize that the tip of your finger is still indeed attached.  Plus the wife will get a bit upset when you run through the house dripping bodily fluids while trying to get to the bathroom.  Pretty neat stuff!

So now I'm thinking that ruderunner makes an EXCELLENT point:

After studying these brakes a bit and finding an old brake tool in my toolbox that used to belong to my dad, I'm going to at least give this a good attempt.  One of the old brake assemblies is complete, and the other is missing only the adjuster and that spring that holds the shoes together across the adjuster.  The shoes still have enough life left in them, but both will need new electromagnets.  After studying them a bit, it looks like the components on the new assemblies just might all fit on the old plates.  That's what I intend to attempt next, but it'll be a few days before I have time to spend on it.

The "complete" old brake plate for reference:



Charlie

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So what did I end up doing? After a good cleaning & inspection of the old brakes, I determined that the critical components (shoes & magnets) had enough life left to continue using for a while yet. The old brake assemblies did have a few components that were missing or too far deteriorated to re-use (adjusters, adjuster springs, and the shoe hold-down springs), so I replaced those with parts from the new brake assemblies. They're now installed, but I haven't yet connected the wires or tested the brakes under tow conditions.

Just for reference in case it's helpful to someone else, in my case I'm convinced that all parts from the new assemblies would have worked on the old brake backing plate with one exception: the actuating arm. On my assemblies, the bushing in the new actuating arm was a little larger than the post on the old backing plate that it mounts onto. But it does have a bushing which can be pressed out, and I'm sure that most any machine shop could turn out an appropriately sized bushing to give it a more snug fit.

I didn't specifically take pictures during much of this process because my greasy and our digital cameras don't go well together. But if anyone wants pictures of anything in particular, let me know and I'll see what I can do.

Charlie