I have an 801 Powermaster... 1950's. The hydraulics won't lift the bushhog. It will lift the box blade, but not as high as it used to. The fluid level is good, but has not been changed in a long time. My son is curious as to whether or not the pump is rebuildable or if it is a replacement only part. He is pretty handy but has not worked on a diesel tractor other than to fix the wiring and replace the alternator. Any thoughts or suggestions out there? I need to mow my pasture as soon as the baby deer leaves with its mother in about a week! I have a 6ft wide bushhog, pretty heavy.