I just purchased a Racor Vacuum gage, part number RK 19671. The boat yard installed it but the tech threw out the paper work and operation instructions. I tried to find the info online, and even called the Racor store but was unsuccessful. Can someone explain what the numbers and scales mean? What number indicates an increasing clogged filter? It is the model with the T handle, and has a set needle and a button to release pressure but not sure how I am supposed to utilize these features.Thanks for any help!
How Do I Read A Racor Vacuum Gage
- Thread starter sammy999
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O C Diver
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The gauge measures vacuum. Vacuum is generated by the suction of the engines lift pump lifting fuel from the fuel tank through the Racor to the lift pump. The height of fuel in the tank relative to the lift pump will show vacuum on the gauge. If you're tank was 20" tall and the top of the fuel tank was at the same height as the lift pump, with a full tank and a clean filter, theoretically there would be no measurable vacuum. As the tank fuel level gets lower, more vacuum registers on the gauge as you need to lift the fuel with vacuum up to the lift pump. You want to know what the normal vacuum values are between full and empty, with a clean filter.
As the filter element nears the end of life (from being fouled) the lift pump has to generate more vacuum to pull fuel through the filter. So, if you know the system has a vacuum of 0 or 1 when the tank is full, seeing a value of 2 or 3 would indicate the filter was starting to get plugged. As the height between the fuel level and the lift pump varies from boat to boat, the numbers aren't as important as knowing what's normal for your boat based on fuel level. Understand that increased RPM means the lift pump is moving more fuel which may mean more vacuum. So determining normal values should be done at cruise.
The tell tail shows the greatest vacuum since it was last zeroed. Ideally you should check the tell tail when doing your normal engine room check. Resetting it really only needs to be done after experiencing a higher value, such as you used most of the fuel from the tank or replaced a dirty filter element.
Ted
As the filter element nears the end of life (from being fouled) the lift pump has to generate more vacuum to pull fuel through the filter. So, if you know the system has a vacuum of 0 or 1 when the tank is full, seeing a value of 2 or 3 would indicate the filter was starting to get plugged. As the height between the fuel level and the lift pump varies from boat to boat, the numbers aren't as important as knowing what's normal for your boat based on fuel level. Understand that increased RPM means the lift pump is moving more fuel which may mean more vacuum. So determining normal values should be done at cruise.
The tell tail shows the greatest vacuum since it was last zeroed. Ideally you should check the tell tail when doing your normal engine room check. Resetting it really only needs to be done after experiencing a higher value, such as you used most of the fuel from the tank or replaced a dirty filter element.
Ted
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tiltrider1
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Simply put, more vacuum, more clogged.
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