I’ve put about 10k miles on my 1950, 3604 since I did the complete brake work.
http://www.pbase.com/dennygraham/image/114877862 The drums were in very good shape, not rusted, not grooved and not over size. They measured about .008” to .010” over the standard size. All that was necessary was a simple glaze braking with some 120 grit aluminum oxide paper. This is a rear but the fronts were in just as good of shape and they were only wire brushed.
http://www.pbase.com/dennygraham/image/114877917 The first 6,000 or 7,000 miles they worked perfectly with a nice smooth stop from highway speeds on down, full hard pedal and you can lock them up if you needed to. But they slowly began to have this chatter as I applied them. And now I’m getting quite a bit of it during every stop. I’d also been getting a little brake squeal so I pulled the drums to clean things up and check for glazing. Every thing looks just fine inside, just the normal dust you would expect after 10k miles. So my ten thousand mile check up consisted of brushing off and vacuuming off the dust, de-glazing the shoes and a light scuff of the drums with, once again, some 120 grit. I also added a 45° chamfer to the leading and trailing edges of the shoe at this time. This was standard on brake shoes years ago but I haven’t seen it in years. Checked and repacked and adjusted the w/bearings, a full grease job and checked the kingpins (which were also installed new 10k ago) and checked newly rebuilt steering linkage and the toe in. A final brake adjustment and we’re ready for another 10k.
I noticed while I was adjusting the brakes that I was getting a tight spot or drag at one point, which of course indicates an out of round drum. Not a lot, just a little drag which is not all that uncommon with an older vehicle that has been in service for a while. However, I now believe that this is the cause of the chatter that I’m feeling. I don’t get the chatter during very hard application of the brakes, as in a panic stop, just during a normal application of them. There is also a very slight barely noticeable pulsing of the pedal.
I’m reluctant to have the front drums turned because they are not grooved and it is impossible to replacements, I’ve been looking for three years and I’ve picked up several spare sets but they are all badly worn and had already been turned well past standard so they are pretty much just door stops.
The other reason for my reluctance is that I can’t find any shops that will arc the shoes to fit the drum after it’s turned. And if I had them turned I would only want the bare minimum taken out and most shops are going to dial in a one pass, .060” cut so they don’t have to take several cuts and sneak up on the cleanup.
So I don’t really know what I’m looking for in this post, probably another answer to where the chatter could be coming from that I might be missing?
Denny Graham
Sandwich, IL
