I am new to walk behinds but I will try and describe the problem the best I can. There is a part in the area of the brake system that must be warped. I believe it has to do with the drum, sheave, or band. When I squeeze the right hand drive lever, there is a warp or rubbing every foot or so that actually grabs the wheel and causes the mower to jump to the right a little. It is almost like if you were to grab brake every foot or so. If I loosen the tension on the linkage, it helps but it is not a fix. Any suggestions will be appreciated. Thanks.