A/C efficiency in a Classic

Discussion in 'Freightliner Forum' started by areelius, Jun 17, 2013.

  1. areelius

    areelius Light Load Member

    Nov 9, 2012
    Temecula Ca
    I have a 2000 Freightliner Classic. I am wondering if anyone else is not satisfied with how cold their AC is when its summer time. Mine works OK when the truck is moving and the engine fan is on, but idleing, it just isn't putting out the cold air I would like. I had it charged but it may have a leak. I would like some advice on what some of you have done to yours.
    KB3MMX Thanks this.
  2. JohnP3

    JohnP3 Road Train Member

    Feb 21, 2010
    Rock Creek B.C. Canada
    Be sure the condenser core is clean in front of the radiator, and change the cabin filter, under the hood right side.
    When the truck is not moving, there is no air movement over the condenser to cool it the AC will not work very efficiently.
    When parked put the fan on manual, and set the idle at 900 RPM.
    areelius Thanks this.
  3. Semi Crazy

    Semi Crazy Road Train Member

    May 13, 2011
    Middle Tennessee
    LOL in Phoenix set idle at 1200!
  4. morr2fab

    morr2fab Medium Load Member

    Oct 3, 2012
    First off 134A sucks. Other thing that can help is to turn on the air recirculation so your not pulling in outside air. Also if you have done that you may have a air recirculation filter too and It may need cleaning or replacement. The system may have to much oil in it and there is not much you can do about that. You may have to much Freon in the system, having more makes the system blow warmer air. Now it could be low as well. It should be about 35-40psi on the low pressure side. It's best to have someone check it the KNOWS AC not some garage. A good working system will only blow air about 50-55 degrees. That's all you can get from 134A. One more thing, the slower your truck motor turns, the lower you have to run the heater fan. Hope this helps.
    areelius Thanks this.
  5. Bakerman

    Bakerman Road Train Member

    Jan 27, 2013
    Phoenix, AZ
    116 last week rollin accross the desert to LA!!
    KB3MMX Thanks this.
  6. snowwy

    snowwy Road Train Member

    Jul 6, 2009
    a average working system will only blow 55 degrees. cuz that's all mechanics cares about.

    all my vehicles blow 35 degrees. and when i actually worked as a mechanic. all my customers got 35 degrees.

    i kick my idle up to 900. and turn the fan on. i can sleep really good in phoenix in the middle of the day. and i've never used my bunk fan.

    i also keep the fan on when it gets above 95. not only for the a/c but also for the radiator. cuz that a/c condensor adds to the heat factor of air being pulled through the radiator. so the radiator not only has a harder time in the summer heat. but the a/c adds to the struggling factor.
    KB3MMX and areelius Thank this.
  7. areelius

    areelius Light Load Member

    Nov 9, 2012
    Temecula Ca
    What is the preferred way to raise the idle speed? Is it done mechanically or through the ECM?
  8. GrapeApe

    GrapeApe Road Train Member

    Jan 7, 2013
    Bump it up with the cruise control.
    areelius Thanks this.
  9. landstar8891

    landstar8891 Road Train Member

    Feb 4, 2012
    NY NY
    I have a 1998 Classic and it SUCKS THE BIG ONE....

    I had all ''condensors'' cleaned (5 hours labor).I had some new O rings and my AC all charged...

    It still sucks....I have new lines and it still sucks...LMAO....:biggrin_2551:I think it is just a whole lot of space to COOL..Try closing your curtain and just use fron vents.That may help...I am with you on the Classic's NON Efficiency AC..

    I give up and i am tired of tossing good money at bad money..It will be Winter here soon and my heat works like a CHAMP...
    fargonaz Thanks this.
  10. bbigcnote

    bbigcnote Light Load Member

    Dec 29, 2008
    northeast, missouri
    2006 classic. Has no cabin filters. i had to clean the evopprater under the dash to get a lot better air flow it was clogged up with dust and other stuff sucked in from outside. since i had to take the lines off to get it out had it vaccummed and new 134 added. shop added exactly what freightliner suggests. on normal it blows around 50 degree air out but if i put it on recirculate it will blow 40 degree steady or sometimes it will get down to 38 or so. the recirulate makes a big difference
    KB3MMX, JB3 and landstar8891 Thank this.
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