radiator flush

Discussion in 'General Motoring' started by Ben, Dec 6, 2003.

  1. Ben

    Ben Guest

    Hi all,

    I was wondering if one can do perform a do-it-yourself radiator flush on a
    95 civic. I like to do it myself, because, everytime a go to a shop on a
    saturday they make me wait for at least an hour, often they ask me to come
    back at the end of the day. If i have to wait that long just to pay
    somebody, i might as well do it myself. Can you share some of your
    thoughts? Thanks.

    Ben, Dec 6, 2003
  2. --------------
    Whatever you do, make sure to use distilled or at least R.O. water when
    you dilute your antifreeze. Tap water can be murder on internal parts.
    Search this group for the consensus on which antifreeze to use. Wrong
    one can wreck your water pump, then engine.

    'Curly Q. Links', Dec 7, 2003
  3. Ben

    Caroline Guest

    If you're at all handy, then a radiator drain, flush, and re-fill is very

    The advantages: Don't have to wait on a shop; you know exactly what was done;
    you can put in the coolant you think is best; you save money; you'll probably be
    more careful; you're calling the shots.

    Disadvantages: Your hands get dirty. You have to locate someone that will take
    the old coolant (not a big deal; state laws tend to be supportive). You have to
    be careful not to leave puddles of coolant (it will kill dogs and cats).

    My 1991 Civic's owner's manual has instructions for this. Maybe yours does, too.
    I would definitely not do this without the manufacturer's instructions.

    I think the most common hang-up comes at the step for taking off the engine
    block drain bolt. A lot of people here, including myself, skip it, because the
    engine block drain bolt is very tight, it's hard to get to, and the bolt head
    isn't optimal. (I did get if off once, however. So it's worth a try.) I just
    drain as much as possible through the radiator drain plug orifice, instead, then
    fill, idle the car, drain, and refill repeatedly until the drainage runs clear.
    I calculate how much water remains in the engine block after the last flush and
    then add undiluted coolant to achieve the right ratio of undiluted coolant to

    I think the consensus here is to use Honda's own OEM coolant. It costs more but
    its guaranteed (by folks here, and there's a lot of experience on this) to
    maximize the life of your Civic's water pump. The water pump is persnickety when
    it comes to coolants.

    I myself am experimenting with the Orange Dex stuff, allegedly designed for
    aluminum engines and imports like Honda, as well as long-life. Thirteen months
    and all's well. But I have the time, money, and inclination to experiment a

    I am thinking of replacing the radiator coolant more often than recommended,
    like 1.5 years or 20,000 miles, whichever comes first, instead of 2 years or
    every 30,000 miles.
    Caroline, Dec 7, 2003
  4. Ben

    JDS Guest

    JDS, Dec 7, 2003
  5. Ben

    MLD Guest

    I basically do what you've recommended but slightly different. In the
    summer--drain using the radiator drain plug. Measure the amount (volume)
    that comes out. Fill with water. Drive for a day and then repeat the
    process. Do this until the water that comes out of the radiator is
    relatively clear. Remember to open the heater a few times during one of the
    daily rides to ensure getting the mixed solution out of the heater too.
    Knowing the capacity of your cooling system and the volume that drains out
    you can calculate how much anti-freeze to put in to ensure the 50-50 mix.
    MLD, Dec 9, 2003
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