On 9/8/02 while delivering our 98 pumper to the shop for front end work the automatic slack adjuster on the right rear brakes became disconnected from the camshaft that operates the brake shoes in the brake drum. Fortunately no damage was done to the inside of the drum or the brake system. The chassis is a 98 Spartan. Has anyone else either experienced this or heard of it happening. The shop was never able to determine why the slack adjuster became disconnected.
Usually the only thing that will allow that to happen is a broken snap ring.Generally after they have been on a truck for four or five years you can't get them off with dynamite much less have 'em fall off.T.C.
Just so we understand what happened, did you find that there was no mechanical failure of the adjuster itself, like the adjusting ring coming out of the adjuster? Was the snap ring which locks the adjuster onto the cam shaft found, or was it missing? When was the last time anyone serviced the rear brakes?
I hate to bring the possibility of this up, but is there anyone who wishes ill on your FD? As Rescue101 says, these things don't normally want to come off, and if memory serves me, not only does the snap ring have to come off, but you have to either disconnect the push rod from the brake can to slide the adjuster straight off the end or else push the cam shaft into the drum an inch or more to get the adjuster to clear the spline on the end of the shaft.
Its possible that the snap ring, for some unforseen reason, just failed, perhaps a manufacturor's defect which resulted in hair line crack of the spring steel, eventually leading to it to split and drop off the shaft. Over time the s-cam shaft pulled itself into the brake drum just by working. Its a long shot, but the alternative is not pleasant.
What do you think 101?