Changing coolant in Ford V-10

Our Class C is on the 2003 Ford chassis with the V10. The Ford recommended coolant is Motorcraft Premiun Gold Engine Coolant and the change frequency is every 5 or 6 years (can't remember which right now). IIRC the coolant system has a capacity of 32 quarts which equals 8 gallons.

The parts guy at the local Ford dealer told me that they use 2 gallons of coolant plus 2 gallons of water when they change the coolant in their shop. Obviously they don't drain all of the coolant out by removing block plugs, etc.

I opened the cap on the expansion tank and the drain valve at the bottom of the radiator and got about 4 gallons out. Added the first gallon of antifreeze and a gallon of water through the expansion tank. I then made a 50/50 mix of the remaining antifreeze by pouring 1/2 the gallon of water into the empty antifreeze container and topping off with the full strength antifreeze. I then added the remaining water to the second antifreeze container. I poured one gallon of 50/50 mix into the expansion tank, plus most of the second gallon. Ran the engine and drove around several times and topped off the expansion tank as needed.

Have done this twice and will do it again before our travels this year.

There's a drain valve on the bottom of the radiator. I usually place a hose onto that to help reduce splashing. If it doesn't look contaminated, a simple drain and fill should be sufficient.

If it looks clean and performs well consider just draining the radiator and refill with premix 50/50 for a shot of additives to limit corrosion.

If you do add any water to rinse or fill... use only distilled. At less than $1/gal it is well worth it.

(In your search the auto part houses had a little vid or youtube)
Here is how I did mine. Couple years ago I asked the same thing. Yes, it needs changed. Make sure you get the "right" type anti freeze (forget what type) I heard people say they had problems with "burping" the radiator and I didn't want to mess with hose. So I picked up a cheap manual fluid pump from harbor freight (under $10) and sucked out every bit I could after jacking up rear end. Pumped into empty gallon jugs so I knew how much old came out and replaced with new the same amount. Kept my eye on the plastic bottle and after driving some, added till between lines of normal.

If I remember right... I also changed the t-stat when fluid was out?

There probably better way but that's what I did. One reason was I can't get rid of anti freeze except a gallon at a time with trash unless I want to take it to our household haz place and wait in line for long time. Worked for me.

If it looks good and tests good leave it alone there is no need to change it.

Yes 12 years is too long.
If still factory, your V10 has the "old" green AF fluid.

When I changed mine I simply opened the bottom valve on the radiator and let it drain.
But then I refilled with pure water and and ran the engine enough to get the system warm (ie open the thermostat), then drained it again.

and repeated
and repeated
and repeated, until I could see or smell no trace of AF.

That way I was certain I got all the old AF out.

I measured how much I drained, so I knew that I had only gotten slightly over half the liquid out at any time. So I used that as a bench mark for how much new AF to put in.

I know that the common recommendation for the ol green AF is every 3 years or 36,000 miles.