Radiator drain?

I have a 2000 S-10, 4.3l that I need to do a cooling system flush on. Problem is I can't figure out the drain cock on the radiator. It isn't the usual wing type, but looks like some sort of weird one way screw head. I can't seem to get it to move. Any suggestions?

Thanks!
Craig

Flushed mine, '01 4.3 S-10, a couple of months back and I garee the drain is a pia, what is wrong with the good 'ole wing nut.
Anyway what I ended up using was a big phillips screwdriver, you could use a large slotted but I happened to have a philips. As far as collecting the old af, that's a pia too.
I got rid of the dexcool, rinsed it a couple of times and refilled with regular Prestone. One caution, I mixed my coolant 50/50, mix it a bit stiffer say 60/40, my freezing point was only -20°. Apparently there's more coolant retained in the system that I thought....Mike

So you really do just keep twisting on it and it will open? I had a flat blade screw driver in the center of it and couldn't get it to open.

Thanks!
Craig

You could just remove the lower hose...

So you really do just keep twisting on it and it will open?

Yep, that's all I did, the actual center didn't come out totally it just moved out....1/4" or so, not much really.
Just be careful it's not seized in there, I wouldn't want to see you bust off the fitting, (damn plastic rads).
I thought about remoing the lower hose as was suggested but, and I'm going from memory here, I think it was harder to get to......Mike

Yep, hose is no easier to get to, and its above the drain plug so won't drain as much. That's my fallback if I can't get the plug open.