workhorse 8.1 radiator cap

Thanks for the replies. One problem is it is difficult to get a grip on the cap due to big air intake tube resting against it. So a marine mechanic here at the camp used a large channel lock on it and did not budge. Not sure if we pushed down hard enough due to the air tube mentioned above. But, on my toad , a '12 grand Cherokee, the cap turns half way then you push down and turn the rest of the way.
looks like i need to remove the air tube (and buy my own large channel lock); other choice is just drive it down the mountain cause i don't
think i lost much coolant. Was pulling the 5000 lb jeep up highway
18 from Barstow to Big Bear ca. When it over heated i unhooked the jeep and drove the rest of the way without trouble. looked like about a pint of coolant on the ground.

It is like not moving at all or moves a bit then stops?

I had one failed on a Blazer and the guy at NAPA finally got it off but had to bust off the plastic grip on the cap and bend back some of the metal on the cap that got bent/deformed the last time it was put back on the radiator.

Never had that happen before in my life.

Best of luck and let us know how it goes.

If a big block gets hot you have an issue to address. In the order of the cap, thermostat, fan clutch then the radiator (blockage external between AC condenser and the radiator or internal blockage or cool fin separation) is my approach.

After 10+ years most radiators could benefit from being recored if copper/brass.

Yes, you must press before turning!

Try pressing down hard and I mean really hard when unscrewing the cap.