Have a 2003 F150, V6-4.2L... Changing the antifreeze myself, but have come across a problem. I can't get the driver side drain plug off. It's a square shaped male plug that I've tried to remove, but have slightly stripped. Don't want to try any more methods and ruin it further. I've already drained it, flushed it, and drained it again. Now I don't know how to get the rest of the water/flush out so I can start adding the new stuff. Draining through the pet**** alone has given me maybe 3 gallons. How do I get out the rest without removing the plugs? Any suggestions? Thanks...

 

Keep filling it, running it, and draining it. When it's all just clean water in there, add 10 quarts of full strength coolant, it will mix with the water and give you the right concentration.

 

Thank you! After failing to remove those odd-ball bolts, and banging my knuckles, I just added 50-50...ran it...drained radiator, and repeated 'till I was out. Thanks again for the help.