This has really got me curious. How do you loosen and drain the coolant at the draincock located under the exhaust manifold? None of my wrenches fit this hex nut. It should be 1/2" by the looks of it. Nothing will grasp it...either too big or too small. There's not enough room in there to maneuver my adjustable wrench.

I'm guessing that i've got an aftermarket plug but i wanted to check here to see if there is a special tool necessary?

If i drain and flush from the lower radiator hose alone, am i going to miss alot of old coolant?

Thanks,
Jon Zaremba