Help with Coolant flush and fill, 2001 Navigator

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Mar 10, 2015
I need to do a coolant flush and fill on my 2001 Lincoln Navigator and I have a couple of questions before I do it.

I have done a coolant drain and fill a couple of times but it was on trucks from the 60's and 70's so I was not to concerned with getting the 50/50 mixture just right and their is a lot less stuff to screw up on an older car.

I want to make sure I get the mixture right when I refill my Navigator and I do not want to screw anything up.

I know most people are going to say to remove the upper radiator hose and t-stat and flush with a garden hose but I do not feel comfortable doing that.

My plan is to drain the radiator and fill it with distilled water and a bottle of Prestone flush and cleaner and then run my engine with the heater on until it gets up to temp real good, then drain that and fill with distilled water and let it run and get up to temp, then drain and fill with distilled water and coolant. Does this sound like a good plan? Is their a better flush than Prestone that I should use?

The previous owner of my Navigator always had Ford flush it for him so I am not to worried about a bunch of gunk in the system, the Coolant does not even look bad at all but it is 5 plus years old so I want to change it.

My manual says that it takes Ford Premium Coolant, which if I am correct is just conventional green coolant? I can get the Ford coolant for $16.99 a gallon, Zerex for $14.99 a gallon, or Peak for $13.99 a gallon. If I don't go with the Ford coolant I am leaning towards the Zerex but I am not sure which one I should go with, what do you guys use?

The Zerex says original green but it does say on the bottle 5 years 150,000 miles, I thought the green does not last that long, does that make this a dexclone and I should not use the Zerex?

My Navigator has rear heat, should I run the rear heater also while flushing the system?

My manual says that my radiator holds 27.9 quarts so that is 6.975 gallons, so I should need to buy 4 gallons of coolant to be able to make almost 7 gallons of 50/50 with distilled water correct?

After I flush it and drain it their obviously their will still be some water in the system, how do I account for how much water is left in to get the 50/50 mixture just right?

Should I mix the coolant with the distilled water before I pour it in?

Thanks for the help and sorry about all the questions, I just want to make sure I do everything right.
You're on the right track. And you don't have to get the mix perfect. Close is good enough and with a hydrometer you can adjust it a bit at a time in the future, if you're worried about it.

Coolant hydrometer.

Change the thermostat. Check all the hoses, even the ones that are difficult to get at like those for the heater core.


Check that the clamps are tight enough and replace any that are corroded.

Hose clamps.

Lubeguard makes an excellent flush and protection products. It's a family owned and operated company that makes everything here in the US.

Lubeguard coolant flush and p rotection.

Sorry about all the links. I'm in the hospital climbing the walls.
Thanks j611, I know exactly what type of for coolant my Navigator takes. I am just not certain if the Zerex is safe to use or not.
As per Motorcraft coolant usage chart, you can easily Google, (Sorry, can't link that in from my phone for you) your engine is safe for gold colored coolant, which Zerex G-05 carries Ford approval for, after a complete system flush as described in the notes in the above mentioned chart.
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I figured I would just stick to the green as that what has been used in my Navigator since it was new, and I am not confident that I could flush all the old green 100% to be able to use the G05.
Does anyone know about how much water would be left in the system so I know how much coolant to add when I refill it?
Originally Posted By: silveravant
I always add the correct amount of antifreeze first, then distilled water. That way you always get the full amount of antifreeze in.

Ok, that makes a lot more sense and easier than mixing before hand. So since my Navigator holds almost 7 gallons of coolant mixed with water then I should add almost 3.5 gallons of coolant and then top that off with distilled water to the cold fill line on my degas bottle correct?

Then any other topping off after a few days of driving around to get to the right level in the degas bottle should be done with distilled water only and no coolant correct?

Once again sorry about all the questions, I am very OCD.
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