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I accidently put Windshield Wiper fluid in the Coolant Reservoir

I accidentally put windshield wiper fluid in my Coolant Reservoir. It was dark and they are right next each other. Of course, I had already driven before I realized the mistake. So I can not just simply pump it out. Will it do any damage? If so, what do I need to do?


  • edited January 2010
    How much did you put in?
  • edited January 2010
    About 3/4 of the container. Filled up the overflow tank.
  • edited January 2010
    That's a lot. I would carefully (it's poisonous) siphon all of the contents of the overflow tank and refill with 50% antifreeze to the correct mark. I doubt much got into the cooling system.
  • edited January 2010
  • edited January 2010
    Don't worry. Washer fluid is mostly water with some alcohol mixed in. The alcohol will vaporize once the coolant comes up to operating temperture, and the worse that will happen is it'll slightly reduce the 50/50 mix of coolant to water.

  • edited January 2010
    But 3/4 gallons? That's a lot of dilution in winter.
  • edited January 2010
    Witness the new slimeball scamming technique - ads buried in a relevant comment...grrrrrr.

    ps - this was in reference to a now-deleted post...
  • edited January 2010
    It's unlikely that the washer fluid will do any damage other than increasing the freezing point of the coolant some. Also, mixing between the recovery tank and the rest of the system is a rather slow process as the fluid from the overflow tank only gets drawn in to mix with the coolant in the radiator, hoses, engine, etc when the car cools off after being driven and the first stuff drawn back will probably be mostly normal coolant pushed into the recovery tank when the car heated up.

    I'd recommend sooner rather than later siphoning all the stuff out of the coolant tank -- or simply removing and draining the coolant tank if that's easier. Don't worry too much about the liquid in the tank. It's toxic, but it's biodegradable. If you spill some, dilute it with a lot of water and forget it.

    Refill the overflow tank to the bottom ("COLD") line with an appropriate antifreeze.

    If you live someplace where it gets REALLY cold, you might want to check your coolant at the radiator cap with a hygrometer just to make sure that you haven't unduly compromised your freeze protection.
  • edited January 2010
    I don't know what year the OP's car is, but most Fords for quite some time now don't have overflow tanks. They have a pressurized degas reservoir, so the fluid was poured directly into the cooling system.
  • edited January 2010
    You're right, many do, but the photo I found of a recent Explorer still shows the overflow tank setup, so maybe the OP's OK.
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