Things You'll Need
John Deere produced the 750 utility tractor from 1981 to 1989. Featuring a 20-horsepower Yanmar diesel engine, it came in both two- and four-wheel-drive models. The transmission and hydraulic system both run off of one pump and share the same hydraulic oil reservoir. Check this tractor's hydraulic oil reservoir often and fill it when necessary to keep it running smoothly.
Park the tractor on level ground, and set the emergency brake.
Twist and pull out the hydraulic dipstick, located below the seat to the left of the gearshift lever. It should have a yellow twist-off cap.
Place a funnel into the dipstick hole.
Pour the hydraulic oil slowly into the funnel. Remove the funnel, periodically, checking the oil level with the dipstick. Do not screw in the dipstick while checking. Keep the dipstick level while it rests on its threads.
Once you have filled the oil reservoir, reinstall the dipstick.
Do not overfill the oil reservoir, which can overpressurize the system and cause damage to the seals.