ovlov760

I remember I started troubleshooting this last fall but then winter arrived and it fell off my list. My AC works perfectly for maybe 10-15 minutes and then stops working. The routine repeats itself after the car has been parked for a bit. From I remember the refrigerant levels were good.

There are no fault codes. Could this be a shimming issue on the AC compressor?

digitaltrucker

Stops working means what? Does not cool? Compressor does not come on? Rapid cycling compressor? Does not turn on? Did you have it evacuated and correctly charged?

ProjectSHO89

Check the clutch gap/ Probably excessive.

ovlov760

It cools really well and then it just stops cooling. I don't hear the compressor cycling.

I haven't had it evacuated it charged. One of those cheap refill kits indicated it was fully charged already.

digitaltrucker

Check it correctly,not with one of those.

ProjectSHO89

If the charge was incorrect, it wouldn't work properly for that first 10-15 minutes. Leave the flipping charge alone unless the data points that direction (it doesn't).

Go check your clutch gap, that's been a VERY common reason for your EXACT complaint. So common, I included it in the HVAC FAQs I wrote more than a decade ago for sister site FTE. https://www.ford-trucks.com/forums/7...xpedition.html

Perform a shimectomy if the gap is too large.

digitaltrucker

Why does a system work well in the cool morning then not in the hot afternoon? Low on gas....while this may not be the cause of his problem, using what he did to check his pressure is not valid, I think you know that though. He needs to verify his system is correctly charged. Have a good one!

ProjectSHO89

Not his reported symptoms.
If it were "low on gas", it would generally work okay in mild conditions but fail to cool well under harsher conditions BUT WITH THE COMPRESSOR STILL ENGAGED. It would not go to a "no clutch engagement" symptom after 10-15 minutes as described.
It's valid enough to determine that the system is not empty and that there is sufficient refrigerant in the system to "make" the low pressure switch enabling the clutch.

FOLLOW THE DATA. ...and go read the FAQs I linked to, this is covered all there.

digitaltrucker

I know its not his symptoms, I was addressing your comment. But he still needs to know that the system is correctly charge to ensure correct operation of the compressor. Good luck!

ovlov760

The shimectomy appears to have worked. The AC stayed on for thirty minutes without an issue. That's a first since I've owned it.

The air gap exceeded .030. I took out the only shim that was present and now the gap measures around .019.

Now that I know the AC can work normally I probably should get it evacuated and recharged.

That was really the last thing on this truck that didn't work right. Thanks all!