Automotive Air Conditioning Information Forum (Archives)

Dougflas on Sat April 23, 2011 5:48 PM

Year: 2005
Make: Dodge
Model: Sprinter

I have a 2005 Sprinter that was purchased used in Sept 2009. I noticed that the R134 level was low and recharged by temps and pressures. I also injected dye. Last month, it was slightly low again and a leak search indicated the high pressure safety valve on the drier was seeping. I ordered a new valve and recovered the charge & replaced the valve. The system was open for less than one minute. I had all equipment ready for evacuation and charging. I did not change the drier. I changed the vacuum pump oil. I pulled deep vacuum. The vacuum equipment was running almost 23 hours. It took that long for the micron level to get to 425microns and hold it. I used virgin freon to recharge.

I bring this up because people always say "I pulled a vacuum for an hour or two." If more people would use a micron guage, they'd see that a 2 hour vacuum doesn't do squat. Of course, the average shop can't tie their equipment up that long. Those out there that have micron guages, try it sometime. I think you'll be amazed.

GM Tech on Sun April 24, 2011 12:27 AM

Just use a decent vacuum pump to achieve the same results in a shorter time. Yours sounds worn out....

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......