Any GM a/c techs here?

[grouch]

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?

 

[96-2D-Hoe]

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

 

[grouch]

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

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.)

 

[dnt1010]

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.

 

[SnowDrifter]

Not a GM certified a/c tech sorry

 

[grouch]

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.

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

 

[dnt1010]

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.

 

[grouch]

Update. I replaced the high side Schroeder valve and put some dye in the system. It worked for about 40 minutes and went dead. I found a leak on one of the lines going to the rear a/c coil. I got a block off kit off Fleabay and capped the two lines. Instead of 44 ounces of refrigerant, I put 30 ounces to account for the smaller volume of the system. The system is still hold pressure and working great. I still blow some onto the windshield but I can live with that. As for the high side port, I still don't get a reading but on my Impala and Dodge Ram, I do. Since this is mainly a winter vehicle, I'm not too worried about it. I do use it to tow during the summer so I can tow with no sweat. (Literally.) Normally, I'd repair the lines to the rear but at nearly $400 each on a 20 year old vehicle with 240K, well the law of diminishing returns kicks in.

I did replace the compressor, reciever/dryer and orifice tube while I was at it. No junk in the tube but leaks on the compressor so I replaced it before garbage got through the system.

 

[Miami-Dade]

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?

Try asking UMMScott in the 2000 tech section.

 

[grouch]

Try asking UMMScott in the 2000 tech section.

I've got it working now. Not quite fixed right but good enough.

Funny thing about the 2000 to 2007 section, I had people telling me I was in the wrong section. ?????

 

[Miami-Dade]

I've got it working now. Not quite fixed right but good enough.

Funny thing about the 2000 to 2007 section, I had people telling me I was in the wrong section. ?????

OMG your right. Thought you had a 99 for some reason. Sorry.

 

[HiHoeSilver]

I've got it working now. Not quite fixed right but good enough.

Funny thing about the 2000 to 2007 section, I had people telling me I was in the wrong section. ?????

That's because of what you already know. Yours is a GMT400. A very few 2000s out there like that. Early escalades like yours, z71 and limited Tahoe's. The rest of the 2000s (the vast majority) are GMT800. The forums are labeled by years, but really, it's chassis (gmt400, gmt800, k2xx).

I'd still ask @UmmScott as suggested if you have questions.

 

[grouch]

OMG your right. Thought you had a 99 for some reason. Sorry.

Some parts I get are for a 1999. Aggravating as all get out when there's a split mid year. Next up, change the steering gear assembly. Two different ones and I won't know which I have until I get it off.

 

[UmmScott]

If you're system leaks youre going to be fighting it and it will be a headache.

Theres no point in keeping charging a system that leaks and leaks fast at that point. Waste of 134a and bad for the atmosphere. (134a does NOT harm the ozone layer but does act as a greenhouse gas)

For pressure testing, get a QUALITY manifold gauge set that doesnt leak. Get a bottle of nitrogen from a local company and pressurize the entire system to 100 to 150 psi.
Observe. It should hold. Mix some dawn dishsoap and water in a spray bottle and go to town. Completely drench the body of the compressor including down by the shaft, any line connections INCLUDING THE gauges themselves. Look for bubbles to appear.

Now wait 30 mins, pressure should NOT move from where you set it. If it does, there is a leak somewhere. If in 30 mins its steady and only drops a psi or 2 i would call that good and evacuate before charging. Yes you NEED to evacuate. Dont just start adding 134a. You dont want air in there!!

Also, if you choose to abandon the rear ac that is fine, just use the weigh in charge for a single evaporator system. You gotta be accurate with the weight if youre using the front ac only. Its an orifice tube and cant adjust itself like the rear unit can.

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