That's strange--I also have an older 150 on my 2000 since about 2004 and it hasn't eaten any brushes. Who'd you buy it from? You should give them a call and talk to them about it. Did it just start going through brushes that often recently, or has it always eaten them like that?
Diesel Dan I think used to be the FASS tech guy that was a member here, but I don't believe he works for the company anymore. I'm not sure if they have anyone else that jumps in on threads like this.
Mike