I have a '99 Durango (5.2L; 4wd; 77,000 miles). I would like to replace the coolant but can't get the radiator to drain. I have tried to open the petcock at the bottom right of the radiator. It will turn 90 degrees but nothing comes out. Is there a trick to this, like turning it 90 degrees and then pulling out. I tried that, but with no results. I know I can pull a hose off, but would like to do this the easy way if I can. I did not heat the vehicle up to operating temperature, as I would rather not deal with hot coolant if possible. I realize that leaves the thermostat closed, but I did open the radiator cap, and I felt that would aid in the drainage. Seems like this ought to be a simple project. Any advice?

 

I did this a while back, and had no trouble. I pulled the lower hose with the cap off, I never have luck with the drains, they tend to get gummed up. I will recommend replacing the spring clamps to screw clamps.