Air Conditioning problem
2008 Dodge Caravan 6 cyl Front Wheel Drive Automatic 88,000 miles
R134 leaking from somewhere that I cannot locate. I have had the dash partially dissembled with no luck finding the leak. It will sometimes hold pressure for a day or two, and cool normally (approx 25 degree drop from ambient). Low side pressure w/compressor running in the blue area on Inter Dynamics can-top gauge. Then there will be the sound of gas venting from under the dash (evaporator, I guess) and low pressure cut-off engages until coolant is added. When this occurs, no obvious odour, 'smoke', or sign of leak detector dye anywhere. I don't know if this is normal expansion valve/orifice sound from refrigerant changing state. No luck with various leak sealers. I have been careful not to overcharge, and the electric cooling fan is running normally. Engine temp is in center of normal range.
Is there a high pressure relief valve that may be activating, perhaps at too low a pressure?
I cannot find a manual for the 2008 year yet, at least not one I'm willing to pay high dollar for!
AC leaks very hard to locate and have to use dye and black light to check for it or a special gas detecting tool
No smell and not visible to be detected by naked eye
Check for a wet spots on the lines and system component
Smoke test also the system can help in locating the leak