Hesitant Gear Change/Possible overheating

Let me preface this by saying I know next to nothing about cars and repairs.

I took my car (1995 Nissan Pathfinder with almost 200,000 miles) for inspection last week. It passed on everything except for “parking brake has excess reserve.” So I took it to the local mechanic and they said it usually just needs to be tightened. After looking into it, they said tightening didn’t do anything because the rear brakes were worn down. They even needed to replace some hardware.

So I get it back and now it seems to have trouble changing gears. It never accelerated all that quickly and this would happen sometimes if it was cold and needed to warm up, but now it’s pretty much all the time. Any ideas what could have caused this?

Also, on the way to work today the heat gauge was a lot higher than normal, not all that far from the H. When I got to work, the hood wasn’t hot or anything (not sure if it would be), but this concerned me as well.

Any info or suggestions would be appreciated.

Changing gears and the added heat have NOTHING to do with the brakes.

Need more information.

What do you mean by trouble changing gears???

How much hotter is the engine running??

I didn’t think so.

When I accelerate, the car revs but doesn’t really go anywhere and then when I let off the gas it will finally change gears. When it does, the car jolts forward. Basically, the gear changing is not smooth.

The marker on the heat gauge is typically a quarter to a half way up towards H. This morning is was more than 3/4 of the way towards the H. I haven’t driven it since then. Nothing else seemed out of the ordinary.

I have a sinking feeling that they messed up the rear brake job and you have a brake dragging. Go back there ASAP. If my hunch is correct this could be dangerous.