Minwy

We've been doing this for years and years with heavy equipment. Different coolant but we've never had an issue with it. If youre worried about heater core corrosion just crack the valve a bit to let a little flow but not enough to heat up the core.

NickBeek

Hero huh? Nahh, I just like to be comfortable. Did anyone find the electric valve listed above yet?

wlewis

Not an electric, but locally Napa has a manual shut off for $14.50.
Part # 6601414. Might save a little time collecting fittings at Lowes or Home Depot.

Spooler

I might have to try this mod because when I tow heavy in the hot summer heat the A/C really performs crappy.

ssandlin

I am also thinking about giving it a try, but before I do, I'm going to have the freon level checked. There have been reports of some trucks being low from the factory.