I'm not sure if you want total refill or top off? In any case, do whatever it takes to bring the fluid level near the top mark on the dipstick. Check with vehicle on level ground with trans in Park with the motor idling. Do not overfill. Add smaller amounts as you near the mark if necessary. In between the marks is what's called "The operating Range" and is acceptable. Don't drive it any farther than necessary when it's below the bottom mark. * ** It's never a good idea to check anything under the hood with the trans in neutral and the motor running unless someone inside the car has their foot on the brake with the parking brake set. **note: the Parking brake is a drum brake that you should not count on to hold the car by itself. That's why the trans should be in Park.