Air leak only when engine running

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by insanityeight, Feb 7, 2022.

  1. insanityeight

    insanityeight Light Load Member

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    2014 t680 will hold air over night, usually dropping to around 40-50 psi. Have replaced numerous fittings to get to this point. With engine idling or running down road it will repeatedly drop to 105 kick in pressure every 6 minutes roughly. Im completely stumped.
     
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  3. BoxCarKidd

    BoxCarKidd Road Train Member

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    Does it do that running with the parking brake set?
     
  4. Concorde

    Concorde Road Train Member

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    West Melbourne Florida
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    I had a 14 t-680 and was constantly chasing leaks..plastic push fittings.

    To me it sounds like something on the accessory side. Your accessory air tank is located behind your driver side step.

    Remove the 4 bolts and check the fittings..right side of the tank. Soap and water in a spray bottle.
     
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  5. insanityeight

    insanityeight Light Load Member

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    Yes. Just sitting in my yard and also driving as well….. anytime the truck is running regardless of whether its rolling or not.
     
  6. Hammer166

    Hammer166 Crusty Information Officer

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    Fan clutch maybe? Turn on the fan see if it still does it.
     
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  7. insanityeight

    insanityeight Light Load Member

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    birmingham al
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    Didnt think of that. Ill try thanks
     
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