Forum Discussion

Budb66's avatar
Budb66
Explorer
May 09, 2017

Engine Coolant Change

How important is it to flush the cooling system with distilled water? To flush my system 3 times would require 30 gallons plus the 5 gallons to achieve a 50% solution.
  • One possible solution is find a friend with a household reverse osmosis water system. Know anyone with a large saltwater fish tank? The hardcore fish owners will use filtered water in the tanks.

    When I did my gas engine I only used distilled for the last flush and the dilution of the coolant concentrate. From what I understand with diesels depends on the engine. Water isn't a high cost item while shop labor is.
  • Doing two distilled water flushes on my 12V right now and granted it's only 4 gallons at a time but it is only $0.88 per gallon.

    I wouldn't put tap water in a radiator.
  • Really depends on how hard your tap water is... If it's really 'hard', then you'll get calcium build up in the rad fins pretty fast..

    Just gotta do what you gotta do... Flush with tap or distilled. Your choice.

    Good luck!

    Mitch
  • I've had my Ford 6.0 flushed along with the Cat C7. A Ford diesesl specialty shop flushed the truck and Freightliner flushed the Cat. They both insisted on using a special flushing chemical and then flushed it once more with distilled water to get the chemical out. The chemical was to remove any rust particles which flushing with just distilled water won't do.

    Bill