Why is coolant coming out of my reservoir overfill when I shut it down? on 1997 Cadillac DeVille

After driving I lose coolant out of my radiator reservoir on my 1997 Cadillac deville when I shut it down. It comes out of the tank where I fill my coolant.

Asked by for the 1997 Cadillac DeVille
poss radiator cap is weak
1 more answer
Try a new radiator cap to start with then don't overfill the recovery tank!