I'm getting ready to do a thorough coolant flush pursuant to the fantastic 40-page instruction manual produced by Mr. Lyon that is floating around here somewhere.

In this manual, it suggests using distilled water with the Restore and Restore + when doing a chemical flush.

After doing the chemical flush, I will be hooking up the city water to the cooling system for a reverse flush.

My question is as follows:

Since I will be using tap water for the reverse flush after the chemical flush, is it necessary to use distilled water for the chemical flush when the system will be subsequently "contaminated" by tap water anyway?

In other words, is there something about the chemical properties of Restore and Restore + that allow it to be more effective with distilled water?

To be sure, after the chemical and reverse flush, I do plan to flush at least once (probably twice) with distilled water before putting the final coolant in.

 

I've not seen this manual. What is the restore flush stuff? Ford has their own flush, VC9 I believe, that works well.

Also, you should definitely do more than one flush with distilled water after. And you should really do more than 2.

 

I did my vehicles several years ago and they are due again. When I switched the F150 from green to HOAT I flushed it with tap water (well water in my case), drained the radiator AND block, then filled with distilled water. If I were not draining the block I would probably run 1 or 2 fills of distilled through. Don't remember exact numbers, but I recall there being about 60% of the coolant capacity in the engine block (ymmv).

 

Use city water to flush out the old coolant, to fill with the Restore for the flush, the blackflushing, and for the first flush or two to get pure water in it before you put the chemical in. I did about 8 flushes to go from old coolant to clear water when I did mine, so after you stop using city water plan on at least 4 to dilute what's in it (I was getting about half the total volume out per drain, so 4 drains puts me at theoretically 12.5% of the original fluid left after 4). There's nothing special about distilled water for the first stages of the process, you just need to use it at the very end.

If this is for a 6.0, I really recommend pulling the lower radiator hose, and take the 20 minutes to drop the starter to put a second Fumoto plug in. That, and putting a water hose into the degas bottle and revving the engine to power flush out the old coolant and flushing chemical. There are video's in the 6.0L forum will show you what to do.

It's the heavy-duty (ie class 8) stuff from Cummins Filtration, popular with the 6.0L guys because one chemical removes iron/ rust (like VC-9) and one removed silicates that have precipitated out of the coolant so you can switch over to a red ELC like international spec'd for the medium duty version of the VT 365.