I have a question about my 1997 walker. I recently mowed a large hill and about 80% through it would no long climb steep. The hydros are making whining sounds only foward. When in reverse it still had plenty of power to climb. It seemed to get worse. I checked the fluid in the hydros and it was perfectly clean with no smell to it. I am assuming (hoping) That I stretched the hydro drive belts to the point that they slip? Or would this not cause the hydros to whine? I assumed this because I can't imagine blowing 2 hydros at the same time and the fluid was clean?