Anyone know what's going on? I went to recharge my AC system after replacing some lines and doing my heater core. It will only pull about 14-16 inHg and loses vacuum in about 15 minutes after I turn the pump off and shut the valves. Consequently, when I fill the system with argon to pressure test (~50psi), no audible leaks anywhere, no soapy bubbles at connection points, and its still holding 50 psi after about 3 hours. I know it was originally leaking out of the high pressure Schrader valve which I already replaced once, so I ended up replacing the whole manifold/line. I don't want to recharge with refrigerant unless I can pull full vacuum (25-30 inHg) and hold it for at least an hour.
AC holding pressure but not vacuum?
- Thread starter vrtillman
- Start date
Sounds like you have a leak under vacuum. Did you replace seals, or did you reuse the old ones? I would recheck your connections.
You do need to be able to pull 30 inHG, but there is no need to have it hold for an hour. I run the leak test for 10 minutes and then recharge.
You do need to be able to pull 30 inHG, but there is no need to have it hold for an hour. I run the leak test for 10 minutes and then recharge.
Old_Crow
TJ Enthusiast
When my a/c failed, the guy pulled a vacuum on it, let it sit for 1/2 hour, and pronounced it good. Serviced it and gave back. A week later, when it quit cooling again, he pressure tested it and this time found a pinhole in the condenser. Replaced that, and it still cools, 3 years later.
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