Where do you put hydraulic oil in a Massey Ferguson 399?

To add hydraulic oil to a Massey Ferguson 399, locate the hydraulic oil reservoir, which is typically found near the rear of the tractor. Remove the filler cap, and use a funnel to pour in the appropriate hydraulic oil, ensuring you check the oil level with the dipstick to avoid overfilling. Always consult the owner's manual for specific oil type and capacity recommendations.