How do you check hydraulic oil in a international 684?

To check the hydraulic oil in an International 684 tractor, first ensure the tractor is on a level surface and the engine is off. Locate the hydraulic oil dipstick, usually found near the hydraulic reservoir. Remove the dipstick, clean it with a cloth, reinsert it fully, and then remove it again to check the oil level. The oil should be between the minimum and maximum marks; if it's low, add the appropriate hydraulic oil as needed.