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How do the tire air valves affect the inflation pressure alarm?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by domtick, Sep 16, 2015.

  1. domtick

    domtick Junior Member

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    Just had new tire installed and now noticing that the original stem cap was not used. Alarm is not lit, but wondering if I should try to retrieve the original one, since we notified the tire shop that afternoon.
    .....or purchase a new one.
     
  2. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    Are they green caps, from Costco?

    My rule #1 when going in there: take the valve caps off beforehand.

    But anyway, any half-decent cap will be effective. They're mainly to keep the valve clean. And provide a slight second-line-of-defence against air leakage, I suppose.
     
  3. xliderider

    xliderider Senior Member

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    The valve caps have nothing to do with the TPMS warning system. If your original caps were metal and now they are plastic, that's a downgrade. But plastic for plastic, probably not worth worrying about.
     
  4. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    OEM are very flat-topped, metallic looking, but actually plastic. I read somewhere metal caps are bad for something, causing valve stems to rust, or?
     
  5. xliderider

    xliderider Senior Member

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    The metal ones I've had were aluminum, so no worries about rust.
     
  6. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    Not really up on it, but reading a bit, see some talk about dissimilar metals. If you frequently take them off to check pressures (always a good idea) then not time for anything to seize I guess. But hey, think I'll stick with plastic.