If the PTO is spinning it should be operating the pump. Onliest way to know if Mr. Pump is working is to put fluid in the resevoir. If the pump is working you should get operation of the hydraulic cylinder unless that has a problem in which case you'll be able to see and hear some activity.
However:
First thing I did was clean everything. Nothing sexy here. Just plain old disgusting scraping, spraying with engine cleaners and hosing it down. Once you visually inspect all the components starting at the actual operating valve, you may just find it's a blown hose or something that needs to be tightened. Check the fluid level in the resevoir. But before you add fluid, fix obvious things that may be leaking first. Otherwise you can end up with hydraulic fluid all over the ground.
