I took a drive up Route 66 to Barstow yesterday to visit guys I used to work with. Round trip distance was probably about 85 or 90 miles. The 33 Chevy ran beautifully. I parked in the garage and went out to wash the bugs off it this morning and couldn't move it in reverse. It would go forward but not backwards. I jacked the car up and it turned out that the right front wheel wouldn't turn backwards. I readjusted the brakes all around and now it moves fine. Has anyone experienced the mechanical brakes tightening up on their own before? I'm glad it was only the brakes. I had visions of the transmission locking up. Here are a couple of pictures of the car at the BNSF terminal in Barstow.
I have had the reverse lock up before but it would release after going forward as long as I did not reapply the brakes in reverse. It does present a problem when unloading from a trailer. The only thing that cured the problem was a product from Kimball-Midwest . It's used primarily for disc brake noise but also helps with mechanical brake noise and operation.
I don't have a proven answer but my thoughts are that the new non-asbestos lining is too aggressive and when applied in reverse the shoes are jammed in place and the springs are not strong enough to retract the shoe. After adjusting and servicing my brakes a zillion times over a two year period I could not eliminate the problem of squealing and locking brakes. The owner of a Meineke brake shop gave me some of the Kimball-Midwest brake treatment product and after using it my brakes are quiet and I have not had a lock up.
It's hard to determine but I am guessing less than 5 % and then only for the first few miles. I notice no difference when driving and can lock the brakes without having to stand on the pedal.
It would be interesting to know if any performance testing was done with similar brake friction material. I write that because the squealing is caused by rapid grab/release of the lining on the thin steel brake drums. That results in oscillation of the drum much like ringing a bell. If the Kimball-Midwest stuff smooths out the imperfections in the drum surface then it might not significantly reduce and might increase the friction.
You can check out the product at www.kimballmidwest.com/801096 . It's main application is for disc brakes and it contains aluminum and graphite powders and it specifically states it works by filling the voids in the brake materials.
