I've lot plently of hermetic systems under my belt but it's been years since I've done a car a/c. Consequently, I need some guidance on evacuating my a/c system.

I've turned the corner on Sybill, the SDL, by installing the new evaporator and starting to reassemble the HVAC 'object' and installing it in the car. Remember, I've replaced the condenser, filter-dryer, compresssor and, evaporator on this car.

The refrigeration connections are now all made and I decided it would be a good idea to pull a vacuum on the system to make sure there weren't any leaks. I ran the pump (a Robinair vane pump) for about 15 minutes and shut it down, closed the valves on the refrigerant gauges and let it sit over night.

Immediately after shut down, the low side gauge indicated approximately 29" of vacuum. After 10 minutes, there was little change in the vac reading (came up maybe 2-3").

After sitting overnight, the vacuum was still there but had decreased to about 18".

I know that mechanically connected refrigerant systems can't hold a deep vacuum but what can they be expected to maintain? Based on the info above, is my system 'tight'? Also, I'm suspicious of the '134a 'adapters' I bought. These gizmos permit you to connect a set of standard R12/R22 hoses to 134a quick connect...they aren't the greatest things I've ever seen so I suspect that they can leak too.

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Never a dull moment at Berry Hill Farm.