hydro problem

i got a simplicity 2690449 from a friend. after approx 30 minutes it wont move in any direction. let it cool down and it rolls again. i'm guessing the pump is bypassing thru a seal/oring. would this be worthwhile trying to rebuild? pumps are $550 for each side and about the same for wheel motors. words of wisdom /advice appreciated. looking for rebuild kit part number if available


amiably,
norwee