AC - Chevy Traverse - suggestions?

[fear_nothing]

AC system had a leak in the evaporator, it was replaced. The AC is now holding a charge (mostly) after a charge, the compressor is kicks on and off excessively as depicted in the video. The system will eventually lose a charge but it takes many hours

With a charge it's still blowing hot air. I found a tiny leak in the high pressure side. A common flaw in this model year, all thanks to some terrible GM engineering.

Should I fix the tiny leak first or source a compressor. Or just do both... Lol

Vehicle: 2011 Chevrolet Traverse
View attachment 20231022_171706.mp4

 

[ZooMad75]

I know we replaced rear a/c lines for pinhole leaks at least three times on different Traverse units at the dealership. It's almost impossible for the DIY guy to do at home as the replacement line set is shipped in two sections. We had a special tool with unique unions to join the lines once they were installed in the vehicle. The line set has both the a/c and heat lines by the way.

I'm not saying it's your exact problem but if you have a leak that you can't find under the hood I'm betting the leak is under or near the rear of the vehicle.

 

[fear_nothing]

Back to the question I guess, the system will hold a charge for say 3-4 hours. If the compressor is in working order, safe to assume that the AC should blow cold during that time?

 

[Wes Harden]

you really can't just assume the compressor is bad with seeing the pressures on both sides. you may have a control valve issue. MY coach had a bad thermal expansion valve and would not cool, new valve same compressor all good. Since you are doing R134a got to Harbor Freight and get their ac gauge, charge the system to the spec on the sticker and run the system. Post up the pressures, outside temps and center vent temp on max ac

 

[Blue85]

Back to the question I guess, the system will hold a charge for say 3-4 hours. If the compressor is in working order, safe to assume that the AC should blow cold during that time?

Yes, but stop charging it until you fix the leak. The way pressure drops so quick is sometimes an indication of undercharge. How much are you adding and how much oil? That oil should lead you to the leak(s). You can also put a little gas in and cover the system with a stethoscope or rubber tube. If you had a proper gauge set it would be much easier to troubleshoot. The ranges on that auto-zone charger aren't really giving much information. It's possible you have a plugged orifice tube, which will cause the quick pressure drop and a lack of cooling. Did you vacuum the air out? If a compressor just starts losing the seals internally, you get higher low-side and lower high-side with reduced cooling.

 

[ZooMad75]

If it’s leaking off that fast it won’t hold a vacuum. That would be the first thing I would look into with a proper set of gauges.

 

[fear_nothing]

 

[fear_nothing]

Answering some of the questions:
Adding 30-40 PSI
* No need to vacuum the system as it leaks down in 3-4 hrs
* Running boards caused a leak, that was repaired w/ splice kit.
* Current small leak is in a terrible spot - haven't tackled that yet. See the dimple.....

 

[Wes Harden]

that the reading static or running ? if static is undercharged, if running is the compressor clutch engaging ?

 

[Blue85]

If the system has had a chance to take on air or moisture you have to vacuum it out. You need to know exactly what's in there. 30-40psi is not an amount, it's a pressure, so you're telling us you have no idea how much is in there. So how is it supposed to work? It's possible you're just not putting enough gas in. Either do it by weight or approximate volume by number of cans/partial. You can tune the charge with thermometers, but you're not that close yet.

 

[Blue85]

I have to admit that I've repaired A/C hard lines before with compression fittings from the hardware store. Usually good for a couple of years until the brass/aluminum interaction becomes a factor.

 

[Blue85]

Also, you learn a lot by touching various parts of the system or shining an IR gun on them. Immediately after the orifice should be cold every time the compressor kicks in - even if the charge is low. When you're getting close on the charge, the outlet of the evap will also be cold. If you have driver/passenger zones those usually split the evap in half. When the charge is right, the further side is getting close in vent temp to the closer side.

How much oil have you added?

 

[Wes Harden]

putting a vacuum on the system would introduce moisture, as long as there is a leak. That is a high pressure line with the leak it will leak our faster the more you use it. Fix the leak. This car uses and expansion valve in the front and rear ac. Sometimes the rear will work when the front does not if so the front expansion valve is suspect.