Western Filter Co.

EcoVent Recirculators

Installation and Maintenance


The Nelson EcoVent Recirculator is mounted in a horizontal position on or adjacent to the engine, and above the crankcase oil level. A connection using flexible heat resistant hose or rigid piping is make between the EcoVent inlet and the engine crankcase breather tube.

The oil free engine crankcase fumes are directed back into the engine creating a closed-loop system by connecting the EcoVent outlet to the engine air inlet stream. These engine crankcase fumes can either be returned ahead of, or after the engine air cleaner. When the engine crankcase fumes are returned ahead of the engine air cleaner, the piping or hose end must be positioned so that the vacuum created by the engine air flow produces a 0" to 0.3" H20 positive pressure reading at normal engine operating speed. A U-tube manometer gauge is provided with each EcoVent. When directly tapping into the engine air stream after the cleaner, a control valve is installed to regulate the initial vacuum so that a 0" to 0.3" H20 positive pressure reading is achieved at normal engine operating speed. After these adjustments are made, no further adjustments are required.


The EcoVent filter element is replaced when the manometer gauge reading is 1.5" H20 positive pressure. To replace the EcoVent element, simply remove the cover clamp and replace the filter element. Note the manometer gauge reading at normal engine speed and make any necessary adjustment to achieve the initial 0" to 0.3" H20 gauge reading.