Bill from Texas, I've never heard of an attachment to true the lining on the vehicle. That would really be an odd one. When I worked at the auto parts back in the early 60's, arcing the shoes was a regular practice. In fact hand lapping the valves was the way I was taught to reassemble a head but thats also not done anymore.
We had a discussion going about a month ago that dealt with the very situation that you discribe. I did a brake job on a '50, 3100 with stock Huck brakes. Even though every thing, and I mean every thing in the brake system was new and the system was pressure bleed, the pedal still feels soft. Upon inspection after a couple of hundred miles my suspicions were correct. The drums were turned a sixteenth over and the shoes were only showing signs of contacting in a small area at the center of the shoe. The reduction in surface contact was only giving the truck about 10 or 20% of its braking power. I determined that the soft pedal was caused by the flexing of the shoes trying to stretch out to meet the drums at the ends.
Will they wear in and will the pedal firm up and will he have full braking power? Sure, eventually, but at the rate that I'm seeing now it's gonna take a couple of thousand miles. Now the one thing that I could not check is whether the relined shoes were actually sized to the standard diameter, if you know a practicle way to determine that radius accurately I'd like to hear it. So it's possible that the shoes were ground to a smaller radius than the standard and with the drums turned to the max so I'm ending up with a compound problem on my friend’s truck. I had no such problem with mine. One thing that I notice on his shoes when I installed them was that they looked like they were cam ground. They were thinner on the ends than in the middle by an substantial amount.
But back to my problem. I was contacted by someone that may be able to arrange for me to use a brake drum lathe to true up my fronts. That would be great. If I had my 16” engine lathe up and running I’d simply turn a standard gauge ring up to check the shoe radius, in fact I could turn up a set of large radius gauges, standard and no go. But alas, I’m a ways off on that lathe restoration.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 09/06/2009 2:40 AM.
