I'd been trying on and off to find this really slow leak on my A/C system for several months now. It's been really frustrating.
Well, I finally decided to really presurize the system to see if I could find it. I used normal compressed air, at about 120 psi and pushed it into the low pressure port on the compressor (I never actually put that much pressure on the system, but it was available). I then immediately heard the hissing of air coming from just above the receiver/drier.
Lo and behold, there was air leaking out of the hard line going from the receiver/drier to the pressure switch. This line runs thru a metal wall, and is "protected" by a foam bushing/gromet just behind the headlight, and under the battery box, so you can't see it without removing the battery tray. The line had worn against the sheet metal and basically cut a hole in the A/C line, hence the leak. Why I didn't hear/see this earlier, I don't know, but it was clear as day once I put compressed air into the system.
Since I've owned my truck since new, I can say nobody had ever worked on the A/C system or anywhere near this line before. So it leads me to think that some of these may have been installed "poorly" in that they may be rubbing too much. You might want to check yours to see how it's doing.
PS: New line is about a C-note since it includes the pressure switch bung, the sight glass, and the union above the ABS gizmo.
Well, I finally decided to really presurize the system to see if I could find it. I used normal compressed air, at about 120 psi and pushed it into the low pressure port on the compressor (I never actually put that much pressure on the system, but it was available). I then immediately heard the hissing of air coming from just above the receiver/drier.
Lo and behold, there was air leaking out of the hard line going from the receiver/drier to the pressure switch. This line runs thru a metal wall, and is "protected" by a foam bushing/gromet just behind the headlight, and under the battery box, so you can't see it without removing the battery tray. The line had worn against the sheet metal and basically cut a hole in the A/C line, hence the leak. Why I didn't hear/see this earlier, I don't know, but it was clear as day once I put compressed air into the system.
Since I've owned my truck since new, I can say nobody had ever worked on the A/C system or anywhere near this line before. So it leads me to think that some of these may have been installed "poorly" in that they may be rubbing too much. You might want to check yours to see how it's doing.
PS: New line is about a C-note since it includes the pressure switch bung, the sight glass, and the union above the ABS gizmo.
