Secondary Fuel Filter Explained

For a little extra protection and peace of mind, installing a secondary fuel filter is a good investment. A standard factory fitted fuel filter usually removed particulates down to between 2 and 5 micron, which is quite fine and ultimately designed to suit the rest of your fuel systems requirements. Pre-filters (10 micron or more) are generally more effective against water, as it gives the water time to hit the filter element and separate. It’s best fitted before the main filter to remove any water before it reaches the finer micron rated factory unit. 

These filter assemblies have a large water collection bowl which allows the operator to visually inspect of water has come from their tank and tried to get to the sensitive engine. Once water is detected it is simple for users to drain this from the bottom of the filter bowl.

Marine filter installation instructions

Drain the water to determine the level of contamination. Inspect the collection bowl for water daily and service as necessary. Replace the filter at least once a year or when servicing your engine.

Draining Water:

• Loosen the self-venting drain plug and drain the water into a container
• Tighten the drain
• Use the primer bulb to fill the filter with the fuel
• Start the engine and check whether there are any leaks

Replacing the Filter:

• Loosen self-venting drain plug and drain the contaminated oil into a container.
• Remove the filter from the mounting bracket with a bowl attached.
• Once the bowl is removed from the filter clean the o-ring gland on the bowl. (Bowl is reusable do not throw away).
• Lubricate the o-ring with oil or grease and re-attach the bowl to the filter.
• Lubricate the top seal of the filter with either oil or grease.
• Fill filter/bowl assembly with clean fuel and attach onto the mounting bracket, tighten by hand.
• Start the engine and check to ensure there are no leaks