so I have a early 90's 753 and drive seems to be week power on the left but on the right side when I go to push forward slowly not jabbing it forward the bobcat kinda shakes doest drive then push it more and then you hit full movement. so there is lack or no slow speed then jerks into full speed or full movement. when you have both sticks forward it doest drive as fast so your always veering to the right. but reverse works fine. so is my pump for that side going out can I replace seals or does it sound like I need a new motor?pump. or a totally different issue