i have a bobcat 642 bought it non running got motor running good but the it always squealed bad when turning. then it would squeal but no longer would turn it would go straight. i have a kid going to school for this pulled pumps didnt see anything obvious. but when reinstalled there is no response if i get the wheels off the ground it will move slowly but i can stop by hand i will try and post video. i have replaced both the main hydraulic filter and the inline on the pump. any ideas