I managed to get a grip on it with a small pair of pliers and with much difficulty, got it to loosen. Once loose however, it's still EXTREMELY difficult to turn. I only managed to get 3 rotations before I gave up and re-tightened it.
The small amount of radiator coolant that trickled out drop by drop wasn't even going though the hose, but leaked out around the fitting.
How many turns does it take to get the coolant to flow out faster than a drip? And why is it so hard to turn the darn thing?

