Why Is My Vacuum Pump Not Pulling Enough?

Welcome industry friends! You’ve come to the right people. What good is a pump with no vacuum? A lot of times the vacuum pump itself is blamed when a system is not pulling a good vacuum. Low vacuum is in fact usually due to needed troubleshooting of other parts in the machine. The good thing is most of the time this problem is easily fixed with some simple adjustments on the system.


The most common causes of a vacuum pump not pulling enough are:

  • Leaks in the system
  • Oil
    • Contamination
    • Wrong Oil
    • Too much/Not enough
  • Foreline Traps
  • Open Gas Ballast Valve
  • Plugged Inlet


Leak in the System

As explained in our first blog, What Is a Vacuum Pump Leak?, vacuum leaks are some of the most common issues that occur in a pumps system. A leak in the system will prevent the vacuum from maintaining its ultimate pressure. This is caused by the pumps inability to efficiently remove the amount of air that is entering into the system. The first thing that should be done is to locate the leak or leaks and fix the area in question. If you are uncertain on how to accomplish this see our previous blogs that explain how to detect and repair vacuum pump leaks here.



Checking the oil in the system is another aspect of maintenance that is forgotten far too often. Contamination, wrong type, or amount of oil can all be the culprits in a pump’s failure to create a full vacuum. You should check the machines oil on a regular basis to ensure that it is clean and properly filled. If the pumps oil is found to be dirty it should be flushed and refilled with new oil. This should also be done if you discover you are using the wrong oil for your type of vacuum pump. Make sure you use the correct type of oil for your specific pump.


Foreline Traps

Foreline traps help to keep oil clean by preventing oil from backstreaming into the pump. Soiled foreline traps can affect vacuum pump pressure and should be cleaned regularly.


Open Gas Ballast Valves

Gas ballast valves are opened to exhaust any contaminated oil. Open gas ballast valves will affect pump pressure and should only be opened when condensed vapors are a concern.


Clogged Inlet

Some operators use materials that act as a protective screen at the vacuum pumps inlet. If the screen is dirty from debris it will eventually clog and create low vacuum levels. Replacement of the screen will fix this issue.


There are many other reasons a pump may not be operating at it’s full potential that can get a bit more complicated. If you are still unable to find the cause of the pumps low vacuum levels, the experts at Precision Plus will assist you in finding the source. We will also provide helpful suggestions for reliable products and practices to keep your vacuum pump functioning at maximum efficiency. Contact us today or visit our website Monday-Friday to utilize our live chat assistance. Don’t forget to check out our blog on pump maintenance. Thank you for choosing Precision Plus!


This is Pete signing out!

Precision Pete's Signature

Leave a Reply

Your email address will not be published. Required fields are marked *