94 Roadmaster Estate drain cock won't open

My car has a plastic drain cock in the left radiator tank. The drain cock seems to only rotate 1/4 turn and since it is plastic I don't want to overload and break it. Is there some trick to how these work? Does it just rotate or do you rotate it 1/4 turn then pull or push on it?

I went to the Impala SS forum and the recommendation there was to avoid using the drain cock at all. They said it is safer to loosen the lower radiator hose than to use the drain cock. The Buick shop manual is no help regarding how the drain cock opens. Still, I would like to know just how the drain cock is supposed to open even though I plan not to try opening it again after reading the Impala SS forums advice.

I believe you turn it clockwise and the screw goes into the radiator, and uncovers a hole in the screw. When it is tightened counter clockwise and presses a seal against the inner surface of the radiator.

I would do as the SS guys advised and just remove the lower hose. Jeff

bamalongroof wrote:

I would do as the SS guys advised and just remove the lower hose. Jeff

X2 coming from a guy who ripped out the pet cock of a brass radiator on his 79 Cutlass trying to do a PM fluid change....
cost of new hose if you accidentally screw it up vs. cost of new radiator.....