Some History. Just bought a used 09 grizzly 450. Only had 10 hours and 40 miles on it. When I test drove it at the local Yamaha dealers lot, I noticed that the rear brake pedal when depressed would not stop the machine. The left hand brake would slow it but not lock up the rear. Dragging my feet would be better. They said they would take a look at. I purchased it. While going over the orientation, the mechanic said that a new $800 rear differential was just installed. This was before they could re-sell it because the previous owner adjusted the brakes and burned up the wet brake system. He said the new diff / brakes were adjusted to factory specs. They are not any better. I think they are blowing smoke and I have the same old differential. Is anyone else experienceing rear brake issues? Or is this how a wet braking system works? Sorry for the novel.