Is brake fluid still good or not?

Discussion in 'Brakes' started by LouisTB, Aug 5, 2016.

  1. LouisTB

    LouisTB Well-Known Member

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    So weather permitting, I plan on doing a full brake job (Pads, rotors, and brake fluid flush). Question is I bought a gallon of brake fluid when I first got the car because the brake fluid was disgusting. So the first thing I did was flush the brake fluid and put new fluid in. Now I'm not exactly sure how long ago that was but it was easily at least a year if not very close. I know that brake fluid hates moisture and has a shelf date after opening, but would it still be good if I've kept it in my room this whole time? I recently tested it with one of those test strips to test the copper parts per million and it showed zero. I'd hate to waste it since there's a good amount left but I definitely don't want to risk putting contaminated fluid in my TB. So I was wondering what you guys thought?
     
  2. Mooseman

    Mooseman Moderator

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    Not sure about copper but it's moisture that kills brake fluid. I have an electronic one that checks the moisture content and says when it should be changed. Do those strips also give moisture? Since brake fluid is hygroscopic, that's what you would worry about.

    Either way, I think as long as the container was kept closed, it should be good.
     
  3. LouisTB

    LouisTB Well-Known Member

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    I'm not quite sure ill grab another test strip from work tomorrow and test it again, ill make sure to see if it says anything about moisture.
     
  4. MAY03LT

    MAY03LT Moderator

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    I had a previously opened bottle that sat for so long that the manufacturer changed their logo before I used it again. I did an emergency repair one sunday night and that was the only fluid available and in it went. No issues whatsoever.
     
  5. Mounce

    Mounce Silver Supporter

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    I figure as long as the lid is on tight you should be fine. Have a little rubber seal don't they?
     
  6. LouisTB

    LouisTB Well-Known Member

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    No rubber seal that I am aware of :/.
     
  7. Mooseman

    Mooseman Moderator

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    Or usually a foam disc in the cap.
     
  8. hockeyman

    hockeyman Silver Supporter

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    Isn't the condensation (that it absorbs) supposed to cause rust within the brake lines, rather than have any effect of how the fluid performs?
     
  9. DAlastDON

    DAlastDON Platinum Supporter

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    Both. Water is easier to compress than brake fluid.
     
  10. Sparky

    Sparky Moderator

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    Compress? Liquids don't compress :confused:
     
  11. Harpo

    Harpo Well-Known Member

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    The water content can become steam when it gets hot and cause very unpleasant surprise, and steam gets compressed and you end up with the brakepedal on the floor.
    Been there done that,barley got it stopped with 50cm marginal.:yikes::wowfaint:
     
    DAlastDON likes this.
  12. Mooseman

    Mooseman Moderator

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    That's right. The water lowers the boiling point of the fluid.
     

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