I was digging out/removing arborvite plants on my jimna 254 when the backhoe stopped working. None of the motions/ valves work. I manually lifted the backhoe up high enough to put a pin in the arm and raised up the stabolizers and strapped them up. The kept going down as the valves are not holding them up. There is no power at all in the hoe. It will not hold with hydraulic pressure if you manuqally move the hoe. Tractor runs fine. Did the pump gobad and how hard is this to replace. Is there something else I need to check. Any help would be appreciated. Rom