Automotive Air Conditioning Information Forum (Archives)

Provided by

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

Archive Home

Search Auto AC Forum Archives

Vacuum Pump Oil Change...

efxengr on Mon August 06, 2012 5:14 PM User is offline

Mastercool Vacuum Pump; 3 CFM, single stage. Is there an accurate guide to how often to change the oil. Each use, every two, etc? From reading the manual it sounds like just sitting on the shelf for a month (in Florida humidity) is cause for change. Would it be better to empty before storing?

Also, if you suspect that a system has been injected with leak sealer (the hardening kind) will that damage the vacuum pump when it contacts air?

iceman2555 on Tue August 07, 2012 9:33 AM User is offlineView users profile

Perhaps I am a bit 'anal' but I change my vacuum oil after every use. The oil serves two purposes, one it lubricates the pump, but also is the seal for the vanes. Moisture removed from the system will accumulate in the lubricant and can become a contaminant.
If this sounds a bit excessive, then change after every evac of a contaminated/burned out system, every wet system (residual flush or high humidity area) and when the lube becomes cloudy.
After all vac pump oil is retaliative cheap compared to the system not being evacuated a sufficient time. And time is not the key to absolute removal of moisture......heat is also necessary to remove ALL moisture, esp in automotive systems. Add additional heat to the system being recovered by running the engine during the evacuation process. This extra heat, often component temps will be well over a 100 degrees enhances the removal of moisture. The best method to determine proper evacuation is the use of a micro gauge.

But back to the vac pump issue. Operate the pump until it is warm, drain the lube and replenish to the specified amount. Never store the pump dry. Always with lube. Prevents damage to the vanes and pump housing. Always use vac pump oil. Never use refrigerant oil, motor oil, castor oil, olive oil (virgin or not) or sex oils.....vacuum pump oil for vacuum pumps. Change it often and your pump should last for years.

This old pump was purchased in the 80's and has always been serviced, many would say too often, but it still works and works very well. It has been 'retired' to supplemental use, the use R/R machines have replaced the unit. But every once and awhile it is required and comes off the back shelf and works very well.

Take care of your tools, they are an investment that pays in dollars and saved time and labor.

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

efxengr on Tue August 07, 2012 11:35 AM User is offline

Great advice, thanks! Especially now that I see how inexpensive the oil is.

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.