Is Boiled Brake Fluid Still Good?

Discussion in 'Tracking & Driver Education' started by jeffjp, Aug 30, 2021.

  1. jeffjp

    jeffjp Rookie

    Nov 19, 2013
    I had brake fluid flushed on my 360 before my last track day. Managed to boil the brake fluid in the last session. Question, if newly flushed brake fluid boils, is it still good or does it have to be flushed again?
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  3. JTSE30

    JTSE30 Formula 3

    Oct 1, 2004
    Austin TX
    Flush it out, everytime it boils it becomes less useful (and will boil quicker each time)

    I recommend you using Motul 600 (DOT4) (not Motul 660), tip: sometimes you can find it at motorcycle shops easier than automotive

    whatever you use, make sure it is DOT4, do not use DOT3 as it does not have the performance characteristics track driving requires

    And when you flush, push out all the old, whatever the capacity is of your brake system, get about a half liter more and keep pushing it all the way through.

    also, if you have rubber brake lines leading up to the calipers, and if you do not know their age, replace them, and, if you can, use stainless (braided or not) lines, they will reduce the amount of moisture entering the fluid (if you replace the lines, do it before the flush)
    turbo-joe, Caeruleus11, Bas and 2 others like this.
  4. jeffjp

    jeffjp Rookie

    Nov 19, 2013
    Thinking exactly along those lines. Have Stoptech SS brake lines waiting to install. Also, I going to try the Girodisk titanium backing plates when I switch to track pads. Thanks for your thoughtful and helpful response JT.
    JTSE30 likes this.
  5. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    The only part that boils is close to caliper. That’s not a lot of volume. Bleed, add fluid, done. System flush on an interval that suits you.
  6. Smiles

    Smiles Moderator
    Moderator Owner

    Nov 20, 2003
    Pittsburgh, PA
    Full Name:
    Matt F
    Just bleed them.

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  8. mdrums

    mdrums Formula 3

    Jun 11, 2006
    Full Name:
    Bleed the brakes each corner starting farthest away from the master cylinder. Blead each caliper until you do not see bubbles. Since you boiled the fluid you will most likely end up doing a complete flush to really get all the air out.

    Brake fluid is cheap compared to not having brakes and wrecking your car and possibly another car and hurting people lives...FLUSH THE BRAKES.
    JTSE30 likes this.
  9. NeuroBeaker

    NeuroBeaker Moderator

    Oct 1, 2008
    Huntsville, AL., USA
    Full Name:
    If someone offered you $100 to drive at 120mph down a straight and brake hard into turn 1 with a 70% chance your brakes would work, 60% chance a few laps later, 50% chance a few laps later, etc... would you do it?

    I'd replace the brake fluid if it was me. I've used Motul RBF-600 with good success on non-exotic cars that required DOT4.

    All the best,
    JTSE30 likes this.

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