I may be wrong but what you actually photographed might not be the drain
cock for the radiator.
Look for a plastic drain cock with two ears sticking out. Unscrew it a
few turns then it should pull out a half inch or so. There should be a
plastic stem on the inside so the drain cock doesn't fall out or get
You might have to get under the vehicle, remove some splash sheilds to
actually see it the drain cock,.
05 Park Avenue 36,008
91 Bonneville LE 306,123