I bought my 2006 Expedition and the A/C was very cold at any outdoor temperature in Colorado. In 2019 The system stopped working due to compressor leak on the shaft. It was the original compressor so no big deal...
I have been tracking two problems since having my A/C system fixed a couple of months abo.
The work done was: Replaced compressor, expansion valve, a couple of the lines, charged the system.
Problem One:
It takes a long time for the AC to cool down when the temperature is 85 and above. It takes about 30 minutes of driving to bring the temp down and it will only get down to 50 degrees.
Problem two:
When the outside temperature is 85 and above the vent temp does not come down to a low temperature even after 30 minutes of driving.
If the outside temperature is:
85 vent temp is 50
90 vent temp is 60
95+ vent temp is 75-80
At 70 vent temp is 40 taking about 10 minutes
At 75 vent temp is about 43/44 taking about 15 minutes
At 80 vent temp is 45 taking about 20/25 minutes
The way the AC was when I bought the truck in 2014 was ice cold regardless of outside temperature within 10 minutes. After around 30 minutes I would usually have to either kick down the fan or turn the temp up because the vent temp was around 35 degrees.
What I did yesterday was:
- Checked out a set of manifold gauges
- Drove truck for 15 minutes on max cool
- All pressures noted below were taken at 2500 RPM
- Outside temp was 85 degrees and the low side was about 37/40 and high side was about 190
- I added some plain R134a (no dye or stop leak) and the charge went high at 60/275
- I vented some refrigerant and the pressures were 30/180 (I know venting to the air is illegal but I did it anyways).
- I went back and fourth with the goal of 55/250
- The sight glass became foamy after going back and fourth so I may have somehow introduced some air.
- It got messy with venting and I became frustrated so I gave up deciding to take back to the shop that did the work.
Any feedback is much appreciated
The only way you can know for sure you have the right amount of refrigerant is to evacuate and recharge the system with the factory load by weight. Trying to "top up" the system by pressures is very hit or miss, especially on a modern vehicle with a variable-displacement compressor.
Stop guessing and let someone who knows what they're doing handle this. At least check the pressures against a reference chart. You went at least 5 PSI too high and then 25 PSI too low on the low side while you were messing with it. Overfilling and underfilling will not allow the system to work correctly. They are precise systems with extremely small tolerances. The only way to properly do this is to fully evacuate the system (the legal way, at a shop with a reclamation machine, not carelessly venting a serious greenhouse gas into the atmosphere) and refill it with a factory charge. The factory charge is under the hood on a label.
Update...
85 vent temp is 50
90 vent temp is 60
95+ vent temp is 75-80
He stated that the thing is the temperature differential. Knowing it performed way better when I bought it even up to 100 degrees and I am sure when the vehicle was new, I find the current high temp performance is sub-par at best...
Again, any feedback is appreciated...