Finding Air Leanks in Oil Line

If you are lucky enough to own an electronic sight glass, you can pinpoint air leaks in the fuel system. Placing the clamps on either side of the devices, you can see where the air is being introduced. The drawings below show us checking for air being introduced at the oil filter.

In the first picture, we are not seeing any air in the fuel system, so we know we can rule out air leaks as a problem. Inspect the fuel pump for any issues. If it were a high vacuum problem, it would show up as an intermittent air problem

Below is what you would see and hear on intermittent air flashing out due to high vacuum issues.

This would be a form of air introduced into the system. Moving the clamps to the left directly on the fuel line, towards the oil tank, and keeping them close together would indicate whether air is introduced before the oil filter. If there is air, check the flange nut and valve packing nut. If no air is detected, the problem is at the fuel filter.
If the example below shows no air moving, move the clamps to another device between the filter and the fuel pump, if one is present. If not, it is sucking air at the flare nut, on the pump, or fuel pump cover gaskets.

Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, and installations should be reviewed on a per-job basis. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for improper information, application, damage to property, or bodily injury from applied information found on this website.