Here you will need a 5/8 and a 1/2 inch line wrench.
The key is to hold the 5/8 still while taking the smaller one off.
I thought that the bigger 5/8 part needed to come out so this was 45 minutes wasted.
Had I looked at my new radiator first, it would have saved me a lot of aggravation

Owner caption December 2009 · Photo 13 of 18