The call came in at approximately 1:30pm on November 25th, right in the middle of Thanksgiving dinner. The problem was linked to the vacuum. When the dairyman turned his system on there was hardly any vacuum. He said he checked for leaks and could not find any. He noted that his Vacuum Controller sounded differently. So we decided that I needed to come out and look at it.

At the farm I found the Sentinal Mark 2 Vacuum Controller mounted above the sanitary trap in the parlor. It was plugged full of dirt and teat dip mist, causing it to stick open and not adjust to the proper milking vacuum. After disassembling it, I washed the controller, rebuilt it and the problem was resolved! And I got home in time to finish Thanksgiving dinner!!

Answer: First, let's talk about what a vacuum controller actually does. There are many types of vacuum controllers on the market, but I believe the most common are the Sentinal Vacuum Controllers. There are four models: The Mark 2, the 100, the 350, and the 500. Each is geared to the size of your particular barn.

A vacuum controller is nothing more than a "controlled leak." It takes the Vacuum from the vacuum pump and emits air into it to hold your system at the set milking vacuum ( usually11.5-15" hg).

When operating correctly, the controller will compensate for any "fall-offs" or small leaks that are emitted during milking and holds the vacuum stable, which is a must for proper and comfortable milking for the cows.

When the controller gets dirty and the filters get plugged, it has to work harder to maintain that vacuum. This is when you start getting erratic readings on your vacuum gauge. In the above-mentioned case, it over compensated at startup and stuck in the open position and could no longer regulate the vacuum.

A dairyman's # 1 responsibility is to keep those filters clean!! At least once a week check your filters. If they need cleaning -- clean them. If they need replacing -- replace them. A $10.00 filter is a lot cheaper than a $500.00 service call plus the time you lost on milking.

Secondly, most vacuum controllers are "air lubricated." This means they must be and stay clean. I recommend once a month to completely disassemble and clean your controller in warm soapy water. If you do not know how to do this, call your local dealer and have them either do it for you or show you how to do it.

Remember: The vacuum controller is the "Heart" of your system. If it is not working properly, you will be in for some big and expensive problems. Three words: KEEP IT CLEAN!!! I want all dairymen to know the importance of keeping a well-maintained dairy facility and the steps they can follow to keep things working in tip-top shape!

Scott Schmidtt has been in the dairy equipment business for 10 years specializing in name brands such as De-Laval, Germania, Universal, Westfalia, Surge, and Mueller. For 6 years he worked primarily with Surge and Westfalia installing new facilities. Scott was responsible for installation, turnup, and troubleshooting during his tenure with West Dairy Equipment/Fowler, Michigan. In 1997 he took a job heading up Scheduled Maintenance and System Analysis's for Central Dairy Supply Inc. Scott specializes in Alfa-Laval Agri, Universal, and Germania equipment. Scott is married to his wife Lisa and has two kids: Mariah (3) and Marissa (4 months).

Scott wants to bring his knowledge and expertise from a serviceman's prospective to our website through question and answer sessions. If you have any questions or are interested in a specific problem, please email Scott at www.smschmitt@cmsinter.net.