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Brake Booster Whine

Discussion in '100-Series Cruisers' started by 2002TLCyes, Feb 14, 2018.

  1. 2002TLCyes

    2002TLCyes

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    I have a 2002 land cruiser, and the brakes work great on it. But I do hear a very faint but still noticeable sound that sounds like a pump working for several seconds. I hear it come on after I've used the brakes for more than just a light tap. I guess maybe it's re-building up the pressure or something?

    I just have never heard this on any vehicle I've driven and want to know if hearing that on the land cruiser is a bad sign, or normal.

    It's not a whine even, and not loud at all. But audible enough for me to notice it.
     
  2. chrisbruck

    chrisbruck

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    Mine's been doing same thing for the past 5 years. It's the booster pump building pressure up in the braking system. Pretty sure the sound is normal and not a failure sign. It's mounted right there at the master cylinder so the sound is in front of you while driving.
     
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  3. 2002TLCyes

    2002TLCyes

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    Ah that's a relief.

    I've heard of some preventative maintenance on the brake system. What would that be? I asked my mechanic and he said since it's a closed system, as long as it isn't leaking, the fluid doesn't need to be changed. Can anyone confirm or deny?

    He said the same thing when I asked him if I need to change the differential/transfer case oils. Ssso the guy really isn't a preventative maintenance person. But I'm curious as to the science behind how gear oils and brake fluids might degrade over time to kill the booster pump/master cylinder whereas timely fluid changes would prohibit that.
     
  4. 2001LC

    2001LC

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    It's just the electric booster pump motor filling the accumulator, very normal.

    Make sure you read what is printed on top of the brake reservoir. It tells how to check fluid level.


    003.JPG 003.JPG

    This out of adjustment will give loud and unusually sound.
    001.JPG
     
    Last edited: Feb 14, 2018
    vman07 likes this.