Re: Ultramafic brake bands

Posted by Ross On 2017/10/16 20:22:51

The servos are both power on and power off so the band has only to spring away from the surface of the drum. Due to the toggle action of the band struts the band is always resting against the drum at some point or another, usually at the gap judging by the typical wear patterns.

I would guess that the difference in the surface texture of the band has to do with the relined ones being shot or sand blasted before relining.

The one band where the edges are not parallel needs a good tug to straighten it up.

The spring RATE is determined by the dimensions of the band and can not be changed unless the metal is thinned. The preload is of course determined by the how much the band has to flex to reach its working position. I submit that as long as the relaxed band is larger than the drum, you are fine. If you feel they don't have enough preload, hold one end in a vise and spring the band open a bit.

Bands are among the least of your worries concerning Ultramatic longevity. All of the various clutches have ample holding capacity----if they receive their design pressure. Now that is the Achilles heel and deserves your full attention, not the bands.