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Brake and battery coolant fluid

Discussion in 'Model S' started by MsElectric, Nov 7, 2014.

  1. MsElectric

    MsElectric Active Member

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    Just curious to see what the recommended maintenance interval is for the brake fluid in the Model S. Does that fluid need to be flushed/replace every certain number of miles? How does this pertain to the new electric brake system. Is that all electric but with a hydraulic backup?

    It seems other than the brake system and the battery coolant system there are no other fluids to be serviced right? Is the battery coolant fluid ever replaced/changed?
     
  2. TES-E

    TES-E Member

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    I would think that the single speed gearbox would need to have the oil changed at some point.
     
  3. EarlyAdopter

    EarlyAdopter Active Member

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    Most brake fluids are hygroscopic, which means they absorb moisture. Over time they get "wet" which significantly reduces their boiling temperature. As such, brake fluid should be changed every two years.

    Unless of course Tesla anticipated the potential of people never bringing their cars in for service and went with a non-hygroscopic fluid (rare). Would be interesting to find out.
     
  4. gavine

    gavine Petrol Head turned EV Enthusiast

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    I read somewhere that this fluid needs to be changed every 15 years.
     
  5. breser

    breser AutoPilot Nostradamus

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    The new electromechanical braking system is still hydraulic, it just replaces the vacuum assist with a electromechanical assist. So yes you still have brake fluid. Tesla recommends that brake fluid be replaced every 2 years/25,000 miles/40,000 km.

    Tesla recommends this be replaced 4 years/50,000 miles/80,000 km.

    Tesla recommends the transmission fluid be replaced every 12 years/150,000 miles/240,000 km.

    Source for all these numbers.
     
  6. MsElectric

    MsElectric Active Member

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    Wow you know what you are talking about :) Thanks for such well searched information! So it seems with major Tesla maintenance we are looking at:

    + Brake fluid every 2 years (25K miles)
    + Battery coolant every 4 years (50K miles)
    + Transmission fluid every 12 years (150K miles)

    Any other major fluid flushes/changes or other major service items I am missing other than small things like cabin air filter, wipers, etc., ?

    So how does Tesla charge for these services? It seems odd they have a fixed yearly service fee when it seems the best thing to do it is to take in every 2 years as that will get you the brake fluid change and the battery coolant fluid change...
     
  7. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    I'd be wary of this one unless someone has a lab report on the fluid and how it changed as miles accumulated. If there is exposure to air (from thermal expansion/contraction via some kind of vent) dust will get in and shorten the life significantly. In the Prius, lab analysis indicates that after 40,000 miles there is significant degradation of the PSD fluid. (Toyota has no change interval for the PSD fluid).
     
  8. dave

    dave Member

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    I'm thinking of getting Tesla to do just the brake fluid this year instead of the full inspection (I do my own tires, wiper blades, etc). Has anyone else done this? Do you know what they charge?
     
  9. apacheguy

    apacheguy Sig 255, VIN 320

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    In they grand scheme of things those are probably the minor servicing needs of the MS. And if you pay for service either a la carte or thru a service plan, they're already included. Major service items would be a master charger or touchscreen failure out of warranty. It has happened and, no, owners were definitely not happy to be forking over several grand for a "low maintenance" EV.
     
  10. SabrToothSqrl

    SabrToothSqrl Active Member

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    2 years on brake fluid? I've gone 15 in my last car with only ever topping it off.
     
  11. scottm

    scottm Active Member

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    Stop much?
     
  12. muleferg

    muleferg Member

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    From the Tesla Manual


    Warning:
    Contact Tesla immediately if
    you notice any significant or sudden drop
    in fluid levels or uneven tire wear.
    Fluid Replacement Intervals
    Do not change or top up Battery coolant and
    brake fluid yourself. Tesla service technicians
    replace fluids at the regularly scheduled
    service intervals:
    • Brake fluid. Every 2 years or 25,000 miles
    (40,000 km), whichever comes first.
    • Battery coolant. Every 5 years or
    62,500 miles (100,000 km), whichever
    comes first.
    Note:
    Any damage from opening the Battery
     
  13. apacheguy

    apacheguy Sig 255, VIN 320

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    Something changed there. I've seen one of the inspection sheets that they use when completing annual service. Battery coolant definitely used to be replaced every 4 or 48,000 miles.
     
  14. marchyman

    marchyman Member

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    Brake fluid is hygroscopic. When the absorbed moisture hits about 4% of the total volume the fluid needs to be replaced unless you like the idea of brake fade due to the presence of air bubbles from water boiling out at the high temperatures that can be generated in brake use. How long it takes to hit 4% varies depending upon where you live. 2 years is a safe number. Another choice is to buy one of these (assuming the Tesla uses DOT 4) and change when needed.
     
  15. ggr

    ggr Roadster R80 537, SigS P85 29

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    The brakes don't fade, they lock up!
     
  16. marchyman

    marchyman Member

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    The typical failure mode is the formation of vapor pockets when the fluid gets too hot. The vapor displaces fluid (which can cause lock-up, but not always). Vapor is compressible. When brakes are applied the pedal may go all the way to the floor (compressing the vapor) without applying the brakes! Brakes can also lock up if the water content is enough to cause corrosion of internal parts and left to sit for a while. That is sometimes a cause of expensive ABS unit failures in my motorcycle experience.
     

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