What to use to pull a vacuum on AC system at home

[old_blue]

Okay, I will repeat...

The $15 cheapies do not pull it down far enough to work below 94 degrees ambient temperature.

hmmm I have exactly that same tool. Hook it to my big compressor (60 gal) and let it run for a few hours. No complaints here. I also live in Arizona so it is pretty warm here regardless.

 

[Mustang5L5]

hmmm I have exactly that same tool. Hook it to my big compressor (60 gal) and let it run for a few hours. No complaints here. I also live in Arizona so it is pretty warm here regardless.

The MAX advertised vacuum for that pump is 28.3 inHg. Even of the pump reaches that...it's not enough.

You need to vacuum down to 29.90 inHg to properly boil off moisture. Unless you have a deep vacuum pump(or a homemade compressor pump) this is very difficult to achieve. Perfect vacuum is 29.921, and usually once you go under 29.00, you switch to a micron gauge. 29.90inHg is 24,500 microns....you need to draw down to 500 microns

Might not be as much of an issue in warm drier climate where higher temps need less vacuum to boil, but for someone living in a cooler more humid state trying to do this....that pump won't cut it.

 

[junkyardwarrior]

What I do is pull it down as low as it will go. 29.0" is about as low as my pump will pull. While it's pulling down, I'll start the engine & let it warm up. That tends to let some engine heat help boil off the moisture.