How the filter works - Fordson page info

Potential Problems. The first problem comes with using the wrong weight oil. (Have clean cannister and 15W40) Use of oil that is too light will cause the oil to be drawn beyond the filter and into the engine. Use of oil that is too heavy will not allow the oil to be drawn up far enough and much of the air cleaning surface area ends up being unused. Manufacturer owner manuals always show the oil weight that is designed for the system. Engineering of the system (we hope) will have picked just the right weight for the size of the cannister, cup, and vacuum pressure. The second problem comes when the cup is not cleaned regularly. Manuals always recommend daily refilling of the cup and suggest even more frequent cleanings under dusty conditions. The oil may look clean in the cup but after a few hours of running but it has trapped a significant quantity of small particles many of which will be drawn back up into the cleaning surfaces. When the particles-to-oil ratio reaches a certain level, the dirt will begin to hang on (or "sludge up") on the cleaning surfaces. Eventually, instead of just clean air being sucked into the intake, you have chunks of dirt and sludge going with it. Obviously this can be quickly damaging to the engine. If your cannister is filled with sludge, clean it out before using it or it could do more harm than good. The last problem is with radically altered machines. The oil bath is engineered for the stock engine. Radical changes to the engine mandate changes to the air cleaning system. Care should also be exercised if replacing your oil bath filter. The replacement should be similar in size and engineered capacity to the original."

So there is a relation ship to that pipe- vacuum to cleaning the air, but will it run wide open without that pipe"

Wayne