2012 international prostar maxxforce 13 air leak

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Cmays0909, Jul 20, 2018.

  1. Cmays0909

    Cmays0909 Bobtail Member

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    Jul 19, 2018
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    Hey guys I’m having a weird air leak on the exhaust side of the engine bay only when I turn the key on and it stops once it reaches 80 psi or if I turn the key off? Any clue what this is because I can’t find where the leak is coming from
     
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  3. Beto0

    Beto0 Bobtail Member

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    Aug 24, 2017
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    soap ans water ando check for bubbles
     
  4. Cmays0909

    Cmays0909 Bobtail Member

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    Jul 19, 2018
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    I know that lol
     
    Beto0 Thanks this.
  5. Heavyd

    Heavyd Road Train Member

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    It is normal to have some air leaking, as there is an air pressure regulator in the air control valve near the turbos. The wastegate and exhaust back pressure valve are air pressure controlled by this valve. If the leak goes away with the key off, it is probably just air out the regulator you are hearing.
     
    hduane Thanks this.
  6. Cmays0909

    Cmays0909 Bobtail Member

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    Jul 19, 2018
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    So when the truck is driving and that air is leaking it’s okay for it to be down to 90 psi? How come it only comes on sometimes? I sat in the truck turning the key on and off for 2 hours and no air leaked, then all of a sudden it started leaking out and stopped at 80 psi every time it leaked. I only drove it once while it was leaking and the pressure was staying at 90 psi even with the truck running.
     
  7. Heavyd

    Heavyd Road Train Member

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    Ok, no, that is different. The amount the valve leaks is very very little and you would never be able to notice any pressure loss. I recommend someone who knows Maxxforces to have a look at this.
     
  8. hoohaa18c

    hoohaa18c Bobtail Member

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    Apr 23, 2020
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    I have this same problem on two of my maxxforces. I have replaced the ACV on both of them once already because they where originally leaking and never had them leak before. Now with a new ACV on both truck they still leak with key on, not only is the air leak audible which makes it technically not DOT compliant but its draining the primary air tank not the secondary air tank. the leaks are coming of the exhaust ports on it, which there are two. I have been inside and looking at i thought maybe i should do a pin out to check if there was a small amount of voltage from the ECM holding the valve open but no such luck. I have no idea why it leaks but there is no way that it is DOT compliant in my mind. I guess if its designed that way it is ok??
     
  9. ChuckMartel

    ChuckMartel Light Load Member

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    Jan 22, 2021
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    It is definitely designed that way and will leak a very small amount with key on.
     
  10. Jimmyk7777

    Jimmyk7777 Bobtail Member

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    Jul 8, 2022
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    Anybody ever fully resolve this issue to their satisfaction?
     
  11. Heavyd

    Heavyd Road Train Member

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    If it leaks only with the key on, that is normal. What are you experiencing?
     
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