Tractor Repair: Ford 3000 hydraulic, piston seal, ford 3000

Question
My Ford 3000 3 point lift bobs, or hiccups. It's done it for a long time. It had a front loader that has been removed. Where I disconnected the hydraulic lines ford the loader (in and out), I installed a hydraulic hose straight from one to the other. I wasn't sure if I should plug them off or not, or if that would have anything to do with the bobbing? The lift still seems pretty strong, no problems lifting.

Answer
  Raise the hitch all the way up with a load on it and then shut off the engine.  The hitch should not go down more than a couple inches in an hour.  If it goes down fairly fast, the lift piston seal is leaking.  When it raises up, it can't hold it and the hitch settles down and the tractor raises it back up to try to keep a constant height which results in hiccups.