I found the coolant drain valve on the bottom of the radiator, but can't get it to drain. The drain is a quarter turn valve. I can turn the valve, but nothing comes out. Thinking that maybe I need to turn the valve then pull it out, like a stopper, I tried that, but it won't budge. I'm afraid to manhandle it too much. Is it advisabke to pull one of the lines going to the engine oil cooler? Those seem to be low enough, but not sure that'll empty the radiator. Can anyone advise? I'm trying to replace the coolant while replacing the thermostat.

 

https://www.6speedonline.com/forums/...07-help-2.html

are you using the Motorcraft thermostat? i flushed system 5 times using the 15 year Prestone product (last post of that thread)

 

I saw you posted this over on pistonheads and got a response and you were able to get it figured out. I'm about to do a flush on mine here in the coming weeks and I have the same drain plug. If I read it right, you were able to just open it fully (1/4 turn to open), and then used some pliers to pull the plug out which got the coolant flowing out of the tap then? Did the plug come all the way out or just partially out?

 

My experience was that I could only get about a gallon of coolant out from the bottom of the radiator with the rest staying put in the engine and hoses. Then you have a choice of what to do next. Crack a hose and handle the splashy mess, or turn the ignition over to get the water pump to refill the radiator a few times.

Either way there was plenty of mess available when I pulled the thermostat housing apart.

Please post what you find works best.

Thanks
Philip