I have a scag belt driven with a sulky. As I'm mowing, the mower slightly pulls to the right. When this happens I have to tap the left brake in order to maintain a straight line. I've also noticed that the right tire has a slow leak, but with the right amount of air is in the tire it stills pulls to the right. I've adjusted the left break and that seems not to be working. The mower is only two years old. Any advise would be great.