[Targa Me]

I have this neighbor who is new to the neighborhood and has rarely spoken a word to me, all our communication has been a casual wave. This past weekend he comes to me as I'm tinkering in my garage and the conversation goes like this:

Neighbor: Hi, how are you?
Me: I'm good.
Neighbor: So I see you work on your car's...
Me: Yup, I do what I can...
Neighbor: You know my truck needs brakes, do you think you can do that for me?
Me: (Trying to be the good neighbor) Umm, sure I can put some brakes on for you.
Neighbor: Great. You know, my mother-in-law's car needs brakes too.
Me: (Here we go...) I don't have a lot of spare time so I don't know if I'd be able to get to her car any time soon.
Neighbor: Oh, ok.

At this point the conversation drindles down.

I don't mind helping out a neighbor here and there, but I don't want to be this guy's personal mechanic either. He didn't offer up a beer, pizza or cash.

My wife thinks I shouldn't do the brakes because of a liability. I'm not sure I want to do his brakes because then he'll start coming over for every little mechanical problem he has.

How do you guys handle a neighbor like this. I guess I might feel different if he offered something in exchange.