DOT 3 in a DOT 4 reservoir...

Discussion in 'The Garage' started by YJake, Mar 4, 2013.

  1. YJake

    YJake Roaming

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    It was an accident, filled the reservoir and went "D'oh" :eek1

    Will I be alright if I just use DOT 3/4 and flush the system with a bottle of fluid?

    I also got some of the Brake fluid on my rear tire... What can I use to get it off and how dangerous is it? :evil

    Thanks all,

    -Jake
    #1
  2. ragtoplvr

    ragtoplvr Long timer

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    They are both about the same, and can be interchanged. Dot 4 has a higher boiling point. But they mix fine. Relax.

    I usually use dot 4 where they specify dot 3 as it is more expensive and hopefully have better anti-corrosion additives.

    Rod
    #2
  3. manic mechanic

    manic mechanic Been here awhile

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    What he said. Given the choice, I use DOT4 when rebuilding brake systems, unless the system calls for DOT5, or even mineral oil in some hydraulic clutches.
    #3
  4. disston

    disston ShadeTreeExpert

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    Wash off DOT 3 or 4 with water. It is water soluble, mixes with water, which is also one of it's problems because it absorbs water from the atmosphere and this causes pitting in cylinders. Change brake fluid at least once a year by flushing with fresh fluid from a new container.
    #4
  5. mbfj40

    mbfj40 Been here awhile

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    Biggest difference between Dot 3-4 and 5 is the temperature rating before the fluid will boil. A lot of the Dot 5 fluids are silicone based and can get a "spongy" feel near it's highest temperature ratings, as well as not absorbing water like the Dot 3's and 4's can, which lowers the fluids boiling point even more. A simple flush of your system with Dot 4 will get you back to OEM specs for the higher temp rating that your OEM called for. In the mean time, at less than race speeds, extreme duty and maximum braking, you most likely aren't anywhere near boiling even the Dot 3 for grocery runs or a casual a ride out for breakfast or lunch.
    safe ridin
    mike
    #5
  6. JimVonBaden

    JimVonBaden "Cool" Aid!

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    Just to clarify, do NOT mix DOT3/4 with DOT 5. You will end up with a guey mess in your brakes that does not work. Dot 5 is silicone based, DOT 3/4/5.1 are glycol based.

    Jim :brow

    PS DOT3/4 is fine for all but the most agressive street riders.
    #6
  7. fast4d

    fast4d Long timer

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    no need to freak. we'll let it slide this time.

    next time buy DOT4:D

    if you can't sleep in peace just flush it out with DOT4.
    #7
  8. scooteraug02

    scooteraug02 Dog Rancher

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    [​IMG]

    Start over.
    #8