Coolant flush question

[rwmorrisonjr]

2012 Expedition with rear HVAC and heavy duty cooling with 176k miles. Following FTM's flush and coolant swap process. Going to change all the hoses, thermostat, and water pump after flushing the system including a distilled water flush. Going to blow the water out of the heater cores before refilling. I've got 6 gallons of 50/50 yellow for the coolant swap after I install the new parts. Will I need a gallon of concentrated coolant first to account for any water left in the block or will the 50/50 be enough since the block will be almost empty?

 

[dcsang]

Firstly, good on you for changing your own coolant. Three years ago I decided to let the local dealer do it for convenience and the result was brown coolant that made a mess of the reservoir within a year. After flushing it again on my own the coolant has been perfect for almost two years. So, what went wrong the first time? I pay close attention when the Expy is being worked on, and I recall seeing the tech take a single 1-gallon bottle of concentrated VC-13-G to the bay. I presumed that was just for top-off purposes but based on the short term-coolant failure I suspect that might have been all the coolant used. It sucks when you're paying dealer prices and getting subpar service.

Those with more experience might be able to offer you reasonable guidance on what might be required to achieve the proper concentration in your case, but I strongly suggest that you purchase a coolant refractometer. The standard is the more costly Robinair 75240, but there are alternatives on Amazon in the range of $20. That will allow you to dial in your coolant ratio without the guesswork.

 

[holeintheice]

Drain and fill. Drive for a day or two and repeat as many times as you want. Or, new parts? Drain it, remove the water pump if you're replacing. Purge air out with vacuum and fill. Will be good as new.

 

[Trainmaster]

I usually add a gallon of concentrated Motorcraft coolant to dilute the pure water remaining in the block after flushing. Then I fill it with 50/50. I also change the thermostat and check the pulley bearings.

 

[rwmorrisonjr]

Water pump, thermostat, seal, and all radiator/heater hoses replaced. Did a full flush with VC-1 cleaner, tap water, and a final 6 gallon distilled water flush. Filled completely with new Motorcraft P-OAT (Yellow) 50/50 since the block was mostly empty after the hose changes. Temp is stable at 195* again, no leaks, and no pulley noises. GTG for another 150k+ miles!

 

[athensdawgs81]

Haven't done my Expedition yet, but on other cars I always flush until clear with distilled water. Then when I take the coolant capacity divided by 2 and put that amount in straight coolant. I do this because its it impossible to get all the water out after a flush, and therefor IMO get a true 50/50 mix when refilling with 50/50. Then I top off with distilled water and then let the water pump do the mixing for me. Over the next few days I top off with distilled water as needed as the air bubbles work themselves out.

At my job working on generators we always fill from the radiator drain with the radiator cap off. This allows everything to get full while pushing all the air out. Not sure if you could rig something up to do that on an Expedition. At our shop will have air pump for the coolant which allows bottom filling.