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Changing engine coolant

Discussion in 'Chevy Trucks' started by thermo, Dec 11, 2012.

  1. thermo

    thermo Member
    from USA
    Messages: 30

    I will be changing the engine coolant in my 03 silverado. I have a few questions about it: 1. It is dex 3 antifreeze correct? 2. How much do I need? 3. Is there a special flushing technique that i should use or just drain and refill? 4. Do I have to use filtered water or will tap water work? 5. 50/50 mix? 6. Where can I get the rubber hose that fits on the drain valve becuase my truck doesnt have it? Thanks for all the help.
  2. theholycow

    theholycow PlowSite.com Addict
    Messages: 1,180

    1. It's dexcool. Dex3 is transmission fluid. Some people hate dexcool and blame it for everything that's wrong in the world but as long as you maintain it on schedule (or maybe a little more often) it's fine.

    2. Can't quite remember...might have to check the owner's manual.

    3. If you're doing it ahead of schedule you can just drain-fill. If you're doing it at 150,000 miles/6 years (or whatever is on schedule, can't remember now) you need to do a standard coolant flush...same procedure as any other vehicle, there's a few different techniques.

    4. You're supposed to always use distilled water. It's next to spring water for a buck a gallon in Walmart/grocery stores. I think I did my flush with garden hose iron-rich well water, then partially flushed that with a couple gallons of distilled before putting in 50/50 distilled and dexcool. (Actually I think I did the calculations and needed to put in 100% dexcool to get a 50/50 mix.)

    5. Yup.

    6. Don't know. Junkyard, of course. Having that hose sure is convenient. Probably can use plain vacuum hose if the nipple is still there.
  3. thermo

    thermo Member
    from USA
    Messages: 30

    Thanks for all of your help. I have havoline dexcool. Is that an alright brand or do I need to go with another brand?
  4. mnglocker

    mnglocker Senior Member
    Messages: 923

    I'm one of the guys who will rip on dexcool and tell your it's crap. If it mixes with air under hear and pressure it crystalizes and plugs up your radiator.

    I run G-05 rated in everything. It's silica free which is the big reason it's good, it doesn't crystalize or erode internal engine parts.
  5. theholycow

    theholycow PlowSite.com Addict
    Messages: 1,180

    I can't imagine a reason why Havoline wouldn't be as good as any other brand. I can't even remember what brands I've used...as long as they're dexcool approved, they're as good as any other.
  6. Plowtoy

    Plowtoy Senior Member
    Messages: 929

    There's nothing wrong with dexcool if its maintained. You need to check it now and again just like you would your engine oil or any other fluids in the system. IMO, I think that 150k is too long to go, but that's what GM recommends. There was a time when dexcool would turn to a mud like substance or eat through a upper intake manifold, but those problems have pretty much gone away with the newer engines (the ecotec? 3800 series III and the newer vortecs (4.8 on up to the 8.1). Its rarely a problem in those vehicles.
  7. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,415

    The 4.8, 5.3, and 6.0 V8's don't have those issues because there is no coolant in the intake manifold.

    But I do agree... less issues with Dexcool if it's properly maintained.
  8. thermo

    thermo Member
    from USA
    Messages: 30

    I got it done and everything went fine. Thanks everybody for your help.