I'm using my 06' MMH for delivering newspapers, so I have a lot of brake usage. The regenerative brakes are working fine, and I know that I shouldn't go through brakes like I would in a non-hybrid. The past few days when I've been backing up, I apply the brakes and hear a rubbing/grinding noise from the right rear wheel area.
In my previous vehicle, when I heard a similar noise, I knew it was the brakes. I replaced them and the problem was solved. Should I do the same on the MMH, and should I do the rotors as well? Or is it probably just the brakes?

 

The only way to know is to actually look at the pads & rotors; there's no blanket answer.

 

Look at the TSB in post #12 of this thread for a possible solution:

https://www.greenhybrid.com/discuss/...go-area-24706/

 

Don't think that TSB applies, at it only happens when going in reverse, never when going forward. I'm going to pull the wheels off tonight anyway. Easy enough to see if the brakes are bad.

How can I tell if the rotors are bad? I just had to have the rotors replaced on another vehicles, and I couldn't tell they were bad when I removed them. But the car drives better when the put the new ones on. These were front rotors, so it was easier to tell when they are bad.

 

Rear brake pads wear faster on a hybrid than the front which may be opposite of what you're used to. On an '06 you probably still have original pads all around which may be a little worse for wear by now. I recently had all my pads replaced on my '07 with 100K+ miles and the braking is definitely quiet now.
I've found its often cheaper to just replace rotors than to resurface them the old school way even though old rotors may still be thick enough to use.

 

Took the wheels off this evening. Still had the FoMoCo pads on. One of the right rear pads was worn down completely. I don't have the funds right now to replace the rotors, but I did put new pads on. I should be able to put together the funds in the next month to do the rotors.

I went for a spin afterwards, no grinding.