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When to add oil , really

SeppW on Tue August 17, 2010 7:37 PM User is offline

I apologize for beating a dead horse, but I really didn't find a definitive answer. Ok, I'm still working on my project; waiting for parts. My question is once I get everything flushed, installed, buttoned-up, leak check and vacuumed down, and assuming I added oil before closing it up, how long could I wait before I get it charged? I'm thinking 24-48 hours wait before I can get it charged, providing the machine works. The vehicle is spec'd for PAG 150, but I'm reading this stuff is very hygroscopic.

So for the leak check I'm pressurizing with nitrogen followed by a vacuum. If those 2 procedures are good to go, I'm wondering if recharging system with nitrogen would keep the oil from absorbing moisture if I have to wait a couple of days to get a refrigerant charge? Naturally, the guy would need to pull a vacuum with the machine before charging to remove the nitrogen.

Or wait and get the oil added at time charge is done. But should I be concerned about condensation that might build in the system if last vacuum was 1 or 2 days old? (Running engine, cooling off, sitting in hot sun and then cool evening/night)



bohica2xo on Tue August 17, 2010 8:37 PM User is offline

You should be fine for a week or two with a bit of N2 in the system - say 35 to 50 psi.

Add the oil, evacuate. Check for gross leaks. Fill with N2 & record the pressure. Check it just before evac & charge - it should be the same.


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~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

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