Any GM a/c techs here?

Discussion in 'General Discussion' started by grouch, Apr 17, 2019.

  1. grouch

    grouch Member

    Posts:
    53
    Likes Received:
    47
    Joined:
    Jan 23, 2019
    Name:
    Paul
    I'm trying to get my a/c working on my 2000 Cadillac Escalade. It's an early model so it's more akin to a '99. I learned early on to get parts for a '99 as the late '00 models are more like the '01. I was trained in servicing automotive a/c systems but that was nearly 50 years ago so I'm familiar with the basics but maybe not the details.

    I vacuumed the system before starting. I hot wired my safety switch so the compressor would engage. The label says it holds 40 ounces of refrigerant. I added 36 ounces plus maybe an ounce of UV dye to look for leaks if it doesn't hold. I'm getting 40 psi on the low side but nothing on the high side with proper gauge set. I suspect the valve on the high side charge port is bad and needs replaced. Input air temperature is 78 degrees and output is 52. So it's working.

    The compressor is filthy and looks like it's been leaking. If I have to open the system, I plan to replace the orifice tube, compressor and receiver/dryer. I noticed one connection with frost on one side and not on the other. I'm assuming this is where the orifice tube is on this model. Anything else I need to replace besides those parts and the hgh side charge port connector?
     
  2. 96-2D-Hoe

    96-2D-Hoe Full Access Member

    Posts:
    125
    Likes Received:
    29
    Joined:
    Feb 14, 2019
    Name:
    David
    Not a GM tech, and no idea if it's the same but on my OBS but my orifice tube is on the output connection of the condenser and is accessed from behind the lower passenger side headlight. I don't think the orifice tube is the 'expansion valve' and there must be some kind of expansion device inside the dryer. I'm guessing the orifice tube converts high pressure liquid to low pressure liquid as there is no noticeable temp difference on my 'liquid line' from the condenser after the tube. Yours may be different. You probably have an HT6 compressor that is also known as a 'belly leaker'. I also need the high side port replaced but mine doesn't close. Rock auto has the complete valve and all parts for pretty cheap.

    Just took a quick look at the parts for a 2000 Escalade and they appear to be identical to my OBS Tahoe.

    There's a couple pics I took recently in this post https://www.tahoeyukonforum.com/thr...tahoe-yukon-today.30709/page-625#post-1328939
     
  3. grouch

    grouch Member

    Posts:
    53
    Likes Received:
    47
    Joined:
    Jan 23, 2019
    Name:
    Paul

    Add a bunch of dirt and grease and your set up looks identical to mine. A supplier I used when I ran a shop is still in business and my account is still there. (35 years later. Prices have gone up though.)
     
  4. dnt1010

    dnt1010 Full Access Member

    Posts:
    208
    Likes Received:
    106
    Joined:
    Dec 2, 2018
    Location:
    Tennessee
    Name:
    Darryl
    High side valve "leak" is pretty typical on these but I have NEVER seen one that you cannot get a pressure reading from? I suspect that your hose end quick connector is not seating down properly on the high side service port? or the pin on your hose end quick connector is damaged in some way and not extending when the knob is turned? Lets do a quick check on your equipment and retest.
     
  5. SnowDrifter

    SnowDrifter Full Access Member

    Posts:
    1,279
    Likes Received:
    743
    Joined:
    Sep 5, 2016
    Location:
    Washington. The desert side not the Starbucks side
    Name:
    Chris
    Not a GM certified a/c tech sorry
     
    96-2D-Hoe likes this.
  6. grouch

    grouch Member

    Posts:
    53
    Likes Received:
    47
    Joined:
    Jan 23, 2019
    Name:
    Paul

    Pushing a small screwdriver into the Schrader valve should have released gas but it didn't do anything. My gauges are in good shape.
     
  7. dnt1010

    dnt1010 Full Access Member

    Posts:
    208
    Likes Received:
    106
    Joined:
    Dec 2, 2018
    Location:
    Tennessee
    Name:
    Darryl
    Only thing I can figure is some clown head used super glue or something to seal it and try to stop it from leaking???? That is bad news as you may find some other SURPRISES! Once you properly vacuum and recharge with the new service port in place, evaluate for leaks/performance etc. and we will have a basis to work off of. If you do not mind use the following to gather performance data. Sufficient run time for system to stabilize (5 to 10 minutes) Windows down / AC controls set to Maxand recirculate / blower set to high with all vents open and Engine RPM at 1500 Now please note Low and High side pressures + outside ambient temp and middle vent temp.
     

Share This Page