How to change coolant?

[VegObsession]

Are there any links or special tips on how to change the coolant? Is it more difficult with the added lines on a WVO system?

Thanks!

[Clay]

I think you need a way to "flush" the system. I take mine to the dealer as they have the proper equiptment to do this. I think i paid 100 bucks for a coolant flush.

[skyskijason]

There is a great 'how to' on this by Gooch over at TDS. It was a sticky forever...

Depends on what you are trying to do. Are you switching to a different kind of coolant? You usually want to eradicate the 'old' kind before you start. First, drain and collect yer old coolant. Resist the urge to let the neighbors cat, who tracks muddy paw prints on your truck every day, drink it. (OK, thats not really funny, even if it is tempting!) You can get one of those 'hose flushing kits' from auto parts or just remove the top hose from radiator and put water in rad and let the 'rinse' water run out the hose. (if ya remove t-stat, this goes alot faster)

This is the key to near total drainage, remove the coolant block drains located below each head. One is kinda behind oil filter on the block and the other is almost hidden above/behind the starter. They have 1/4" square (socket driver) plugs. (Another DFA-forum exclusive tip - replace the PITA plug above starter w/a drainc0ck!)

I always do a few more flushes w/distilled water. Ya don't want ANY tapwater/wellwater in there, its not good (minerals, chemicals, etc). Then, add coolant of your choice. If that coolant requires water, use distilled and don't bother draining the block after the last 'rinse' w/distilled.

The 7.3 holds about 8 gallons of coolant w/'normal' VO loop.

MAKE SURE TO ADD 'SCA' if req'd with your coolant.

I just changed the coolant in the Excursion and chose CAT ELC as a coolant. This 'extended life coolant' is designed for heavy duty diesel engines and surpasses all the requirements for our engines, by far. The trouble is after 300k miles, ya have to add an 'extender' from CAT to get the full 500k miles life out of the coolant. (tounge in cheek)

I used Evans NPG+ in my F350. That stuff is 'special'. First, it is a lifetime coolant, never needs to be changed. For that reason, I added a coolant filter to my system. Its special because it is 'waterless'. It does not boil until 375*F, at 0psi . I chose this because I figured w/all the potential leak points I added w/VO system, it could not hurt to eliminate the pressure in the cooling system...

If you're changing coolant, you should change t-stat as well. (they don't last forever!) The ONLY t-stat a 7.3 VO conversion should be running is the 203* t-stat from www.dieselsite.com. The billet t-stat housing is a good choice too, the factory thin-tin POS is considered 'not re-usable' by Ford and often rusts through anyway.

Good luck! Ya might as well spend the $100 ya saved DIY on a new, better t-stat and housing!

[skyskijason]

Is it more difficult with the added lines on a WVO system?

Thanks!

I'll add that I usually unhook heater core hoses and flush it seperately - same applies to VO coolant loop.