What’s the army reserve like for a 91B?

Depends on the unit. We have 91B's at the Field Hospital and they don't do a whole lot. I can't speak for other units though.

Depends on the unit you go to. Generally the Reserves is not made up of combat power, so you get a lot of support units, units, that IMHO, don't kill themselves on maintenance. "We got mechanics, we can let them do all of that stuff." You will be slaving off vehicles, oil sampling, airing up tires, changing tires because operators are dumb a$$es and don't bring their BII. Real mechanic related stuff occurs on Annual Training.

In my experience as a Quartermaster Company Commander I had an entire platoon (among 4) of mechanics to support our equipment. These were Refrigeration techs, Generator techs, Vehicle mechanics and their Platoon SGT.

When not at home Battle Assembly and in the field they generally would be used to keep things going the best they could. You might be pulled out during a battle assembly to make sure things are ready for a big exercise because the last thing you want to find out is something doesn't work when you try and roll out.

Now............ what is likely to happen is if equipment is straight up broken and out of your capacity it repair on the spot with on hand parts then that's that. A work order for an AMSA shop to fix it will have to be done.

There is a possible chance you could be put on orders to fix a bunch of stuff over the course of several days. However, that takes a VERY proactive motor SGT to line up all the parts, get them ordered and in the hands of the unit, and create a work flow where orders can be justified with an end goal of equipment readiness improving.

The ONLY reason my unit was able to have such orders issued for mechanics to come on to fix things was we were co-located with an AMSA shop. So they had our parts. Otherwise we would have to convince battalion to NOT put in a work order at AMSA and send up the parts instead and TRUST it would get done.

Basically, a work order would be put in, and AMSA would never get to it, we'd say, well don't you have the parts? They say yes, and we could convince Battalion to issue orders then and we'd go across the lot and get the parts already allocated to our vehicles.