Question about 2000 Dodge Ram 1500 Truck

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AC Vacuum Leak

When accelerating cold air turns into hot air, usually when this happens I can decellerate and have cold air once again, when this happens I always hear a damper door close, help

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  • desertladi Aug 04, 2008

    Thanks greasynail1, I will check this out

  • ruthgeana Aug 16, 2008

    When I hit my brakes, my cold air turns into hot air. But when I turn the A/C off, then back on, it's fine until I have to stop again?????


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The temp blend door is operated by a vacuum motor.At higher engine rpms the manifold vacuum decreases.Most manufactures incorporate a vacuum storage tank to compensate for this lose of vacuum.So it does sound like you have a vacuum leak to the ac control unit.There should be a vacuum line going through the firewall into the cab.Inspect this line for leaks.Good Luck!!!!

Posted on Aug 04, 2008


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Drive the car up to 55 MPH with the AC on. Making sure there is no vehicles close behind you,completely let off the gas pedal and see if it starts blowing cold air right after letting off the throttle. If it blows cold, then it's probably a vacuum leak.

If it doesn't blow cold then it could simply be low on freon or a partially clogged filter in the AC line.

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The reservoir was a metal can (like a tomato juice can) at one time but if my memory serves me in 1986 they went to a plastic version.

Take care and thank you for using FixYa.


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