Peterbilt 379 AC problems

Discussion in 'Trucks [ Eighteen Wheelers ]' started by bigstank, Jul 26, 2015.

  1. bigstank

    bigstank Light Load Member

    87
    18
    Mar 4, 2013
    missouri
    0
    Hey guys gotta question for ya. 03 peterbilt 379, I just had the whole AC system replaced. Compressor, accumulator, lines, expansion valves and everything for the bunk AC also. Now my problem is, at idle or 900-1000 rpms The AC blows 45 degs but when I take off rolling down the highway the AC blows about 58degs. Now my pressures are fine and freon is right on the money according to the machine. I'm kinda just lost here on this issue. The AC never had this problem for 6yrs until the old compressor blew the front apart..... thanks
     
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  3. pop's

    pop's Light Load Member

    54
    16
    Feb 3, 2013
    Yulee FL.
    0
    Change the condenser.
     
  4. bigstank

    bigstank Light Load Member

    87
    18
    Mar 4, 2013
    missouri
    0
    I did brand new one put one
     
  5. Straight Stacks

    Straight Stacks Paper Cha$er

    2,930
    20,768
    Jul 18, 2015
    Alabama Gulf Coast
    0
    Most places add dye as standard operating procedure. At least I know the TA's, my local shop and the Peterbilt dealers I've used over the years have. Something may not have been installed tightly enough, or may have just wiggled loose ie. hoses
     
  6. 062

    062 Road Train Member

    5,852
    31,731
    Oct 20, 2013
    0
    Is the fresh air door hung open?
     
  7. dustinbrock

    dustinbrock Road Train Member

    1,306
    900
    Apr 19, 2012
    saskatoon,sk
    0
    try turning your setting to recirculation instead of fresh air

    check the coolant lines coming off the engine head and see if there is a valve you can shut to kill the heat in the cab.
     
  8. bigstank

    bigstank Light Load Member

    87
    18
    Mar 4, 2013
    missouri
    0
    I've got the water knob off and always use recirculation. Idk it's got me puzzled
     
  9. kennry

    kennry Bobtail Member

    15
    3
    Sep 4, 2015
    0
    Are you sure the bunk ac is working
     
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