Hi there, I recently bought an old bobcat 641 for $1000. It had been sitting for at least 10'yrs. So far, I've : -rebuilt lift cylinders -rebuilt tilt cylinder - repaired leak in oil cooler - replaced 1 dry rotted hydraulic line . The bobcat drives fine ( a little jerky). The tilt seems to work fine and can raise the front wheels off of the ground. The lift, however, has very little power. It can barely lift the bucket and is very slow I tried adjusting the relief valve , but no luck Any help would be much appreciated