If your truck has automatic slack adjusters and they need manually adjusted something is wrong and it should be looked at by a mechanic. Automatic slack adjusters should never need manually adjusted.

Originally Posted by Evil_E

Are we as drivers even allowed to make adjustments? Seems like you would need a certification for such things. I know we are required to inspect and report, but not 'tamper'

This is correct. They are supposed to be adjusted by certified people. Check yes. Adjust no.

some companies certifytheir drivers, I was certified by Jb 11 years ago, but without a card saying that they have to checked by a pro. plus like most have posted automatic adjusters shouldnt need to be unless they are bad

I have found automatice slack adjusters, adjust themselves correctly for approx. the first year to two years unless tampered with incorrectly.
If one needs to cranks the adjustment backwards, this wears tremdously on the automatic gears. So if you adjust to tight and have to back them off very many times, they will stop adjusting automaticlly.
So you shouldn't have to adjust them unless they are not working correctly.

Plus it may not be the adjuster that's bad...a worn cam bearing can put slop in the slack adjuster, tightening the slack adjuster just makes the problem worse and can ruin the slack adjuster as well.