Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

Vacuum Question

MHardee on Thu June 04, 2009 4:40 PM User is offline

Dumb question of the day...
Why does a vacuum pump not pull out the oil in a system? You take all of the steps to place oil in the compressor and Accumulator and then you apply vacuum. It seems that the oil would be pulled out as well?

Dumb Question #2..
I've seen plenty of folks add oil to the system after vacuum and leting the vacuum pull oil in.. Is this a bad practice?

Thanks

Puzzled in Tennessee..

-------------------------
True Shade Tree

HVargas on Thu June 04, 2009 6:59 PM User is offlineView users profile

The reason it pulls just the water out of the system is because when the system is placed in a vacuum it boils the water out of the system and oil and removes it.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: Arizona Mobile Air

fonebone on Sat June 06, 2009 12:52 AM User is offline

Hi MHardee; Adding oil that way is fine, if you have the special tool. If you know you needed oil when you had the system apart, then put it back together, then realized you forgot to add it, that is the way to do it. You add it when it's apart,and opened up, or when you assemble it and vacuum it out; either way. Better, of course when it's apart. (easier!)

Cussboy on Sat June 06, 2009 10:57 AM User is offline

Quote
Originally posted by: MHardee
Dumb question of the day...

Why does a vacuum pump not pull out the oil in a system? You take all of the steps to place oil in the compressor and Accumulator and then you apply vacuum. It seems that the oil would be pulled out as well?..

Water is volatile and refrigeration oil is not, it's chemistry and physics. Pulling a vacuum does at least four things:
(1) It pulls air out of the system.
(2) the vacuum (reduced pressure) enables water to boil (boil out of the system) at ambient temperatures; at atmospheric pressure 212*F is needed to boil water).
(3) If the vacuum holds steady after vacuum and shutting off valves, it can be an indicator of a leak (note "can").
(4) The resulting vacuum is an easy way to add the first charge of refrigerant.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.