I have added tranny fluid after losing fluid and it still slipping but working better but it only slips if you slam on this e gas if you gradually step on the gas it works fine. lost 4 to 5 quarts of fluid after tranny cooler line popped off from doing a water pump change. I know i disconnected the entire radiator when i should have left it connected at the A/C and tranny cooler lines but i was just trying to get more room to work with and now i am going to be bittn the bullet if i fried a trans instead of paying gmc 900 BUCKS to do it so i save 800 but may have to spend 1200 or more to fix or replace tranny 