Remove the cap from the fill reservoir for the hydraulic oil. The reservoir is located just behind the driver's seat of the John Deere tractor.
Pull the dipstick out of the tube on the John Deere tractor. Check the level of hydraulic oil that registers on the dipstick. Do not add hydraulic oil to the tractor unless the level is low.
Insert a funnel into the fill tube. Slowly pour the hydraulic oil into the funnel. Check the fluid level frequently. Stop adding hydraulic oil when the dipstick shows the level is full. Replace the cap on the fill tube.