Gilberto Padilla

It was pretty clear after I flushed it out. The second time I only drained the radiator. The coolant came out dark brown the second time. This is what I did:
Drained radiator
Replaced thermostat and gasket
Screwed thermostat housing back on
Filled radiator with distilled water
Turned truck on with heater on full
opened radiator drain
Poured 3 gallons of distilled water into radiator while truck was running/draining
Turned truck off
Filled with VC-1 and distilled water
Turned truck on, revved to 2500 rpm for about 15 mini with heat on full.
Drained radiator.
Refilled with 60/40 coolant mix.
Drove truck for a day.
Drained radiator again
Refilled with 50/50 mix

Not sure if it's the best way, but I hope I got most of the green coolant out.

Upgraded2Ford

you did....guarantee it.

Gilberto Padilla

Thanks, I hope so.

AmericanEOD

2010 5.4 F150. Opened the petcock, about 2 gal came out including the overflow tank. Filled with distilled water, ran about 15 min, drained and repeated. Drained until nothing came out of the petcock.
Used 50/50 and filled the radiator, burped the system, filled it again. Replaced the radiator cap. Filled the overflow and replaced the overflow cap. Ran for a while and added to the overflow.
I am concerned about the water remaining in the engine. Should I have used concentrate rather then 50/50? It has been two days and the coolant does not look like it has thinned out.
And why did I buy 5 gal of 50/50 when I only needed 2 gal?

Bwelch22

When you say replace the radios cap and reservoir cap are you actually buying a new cap? I haven’t seen any use the motor craft cooling system fluid that’s recommended for the flushing the system.

Caldwellfam2018

did you ever find the answer your looking for? I’m plagued with the same thing right now. Bought 5 gallons and only used 2.

laterongc

you need to calculate the water that is in the system/engine that doesn’t drain out. I have an 11th gen, but assume it is ~ same. Plan/estimate that ~ 2 gallons stays in engine after fully draining. So you add 2 gallons of 100%, then top off with 50/50 (probably a little less than a gallon of that). Use can test mixture too when done to ensure you are in safe zone.

if you’ve done a proper flush and have 100% water in engine, you’ll never get it right without using 100%

hope this makes sense