System Evacuation Question

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, JohnHere, Dougflas, HECAT

Posts: 14
Joined: Sun Jul 10, 2016 11:40 am

System Evacuation Question

Postby 69-er » Sun Jun 30, 2019 1:32 pm

Theoretical Question:

When evacuating a system, any water turns to vapor. Where does it go? I don't see how the vacuum pump "sucks" it out as there is no flow going on; it's a static condition.

Given that, once a pump gets the system to its highest vacuum wouldn't turning off the pump have no affect on the evac procedure? If there is no leak in the system the vacuum stays the same whether or not the pump is running.
Posts: 299
Joined: Mon Apr 18, 2016 6:10 pm

Re: System Evacuation Question

Postby Dougflas » Sun Jun 30, 2019 3:44 pm

When you apply a vacuum, you are boiling off the moisture. You can not measure this unless you use a micron gauge. Your manifold gauge will indicate -29 ish but a micron gauge will indicate how much vacuum you're actually pulling. I suggest watching some You tube videos on pulling a vacuum.

Return to “Automotive Air Conditioning Forum”