5 Maintenance Tips for Cleaning Your Spin-On Fuel Filter

If your boat engine is sputtering, losing power, or is difficult to start, one of the likely causes could be a problem somewhere in the fuel system. It could be air in the lines, fuel contamination, or a clog in the filter. One of the easiest troubleshooting activities is to confirm the proper operation of your spin-on fuel water separator.

If you’re wondering how to clean a spin-on fuel filter, the short answer is that you don’t. It’s a part that needs to be inspected and replaced on a regular basis. You can either replace the filter element or the entire filter assembly. This decision is based upon the physical condition of the various filter components.

It’s a fairly straightforward job, and not a place to try to pinch a few pennies. If your spin-on fuel filter gets blocked, your boat is not going to operate properly, and if not promptly addressed, this issue could lead to damage to your engine system. Let’s look at some maintenance tips to help you check and replace your filter properly.

1. Inspect

The first step is to inspect the filter for any leaks, obvious damage, or other issues. Visually inspect the filter element housing and entire assembly to ensure it doesn’t have any cracks, excessive water, or contaminants, including dirt, in the drain bowl. If any of the components are cracked or damaged, it is time to replace the entire filter assembly. If the drain bowl has dirt or other contaminants, this is an indication the filter is dirty, and it is time to replace the filter element. If the drain bowl is full of water, you will need to place a container under the drain bowl, open the drain bowl plug and drain the water. If you are performing this “draining” activity on a regular basis (i.e., every few days) this may be an indication your fuel tank has a large deposit of water in it, and you will need to discuss solutions with your marine mechanic.

2. Pick the Right Replacement

It is important to get the same size and type of filter as the one that is currently in your boat. This does not necessarily mean replacing your filter with the same brand, rather that you just need to make sure the filter capacity, micron rating, and thread sizes are the same. As a general rule of thumb for most marine applications, a 10-micron filter is recommended.

Once you know what filter you need, it’s a good idea to have a spare on hand since a tank of bad gas can quickly plug the filter and leave you stranded. Store the extra filter in its original packaging in a cool, dry environment.

3. Replace

Depending upon the results of your visual inspection, you will either replace the filter element or the entire assembly. If you are replacing the entire assembly, you will simply detach the fuel lines from the filter, disconnect the assembly from the boat, and replace with a new filter assembly. For either replacement option, don’t forget to place a container under the assembly to catch any fuel which will leak during the replacement activity.

If you are replacing the filter element, there are four key things to remember: remove, inspect, oil, and tighten. Remove any water from the drain bowl prior to removing the filter element. Simply open the drain valve on the bottom of the drain bowl and drain the contents of the bowl into a collection container. Now you’re ready to remove the filter element. Because spin-on filters are often installed in ways that make them tough to access, you might need to use a wrench strap to remove the filter. As a simple suggestion, you can use a bit of sandpaper between the strap and canister, which will help you get a better grip on the filter.

After removing the filter element, you will need to remove the drain bowl from the element housing. You can use a simple filter bowl wrench along with a wrench strap to disassemble these two components.

Prior to installing the new filter element, perform a simple visual inspection of the new filter to ensure it doesn’t have any defects or damage. If you can see any defects, that filter should be replaced with an undamaged one.

After this inspection, you will need to apply a thin layer of engine oil to the surfaces of the O-ring and filter element gasket. These two components should be included with the new filter element. After oiling, install the O-ring in the top of the drain bowl and the gasket in the top of the filter element. Note, never re-use the existing O-ring or gasket! Reuse of these components will typically cause the filter to leak fuel.

When it comes to reassembling the components, gently thread the drain bowl onto the filter housing, making sure the O-ring does not get “pinched” during the assembly process. Hand-tighten the bowl onto the element housing. Next, you will need to fill the filter with fuel (80% full). This will help to prevent any air bubbles from entering your fuel lines. With the filter full of fuel, carefully attach the filter element/drain bowl assembly to the diecast cap. Again, gently thread the two pieces together and be sure not to overtighten the parts. These components should be hand tightened (firmly) to ensure that they are not inadvertently overtightened.

4. Mark the Date

When you get ready to install a new filter, write the date and current engine hours on the outside of the filter housing. This will help you to keep track of the total hours the filter has been in use, and when it is time to replace the filter.

So when is it time to replace a spin-on fuel filter? It is recommended to replace the complete assembly annually, typically at the beginning of the boating season. The filter element should be replaced every 400 hours of use. Additionally, if you’ve started noticing start-up issues or rough idling, it’s time to perform the above inspection and possibly follow up with a filter element replacement.

5. Take Care with Fluids

When you replace the filter, remember you are handling a flammable fluid. You want to be careful not to spill fuel on the deck as that can be a recipe for a boat fire.

There are a couple of different methods to catch any fuel flowing out of the filter during the replacement process. You can either place a heavy-duty plastic bag around the filter while you unscrew it, letting the fuel drain into the bag. Or, you can set up a catch bucket under the filter to catch and contain any fuel run-off.

Also, be sure your engine is off and everything is cool to the touch before you start unscrewing the filter. Follow good safety protocols with fire suppression equipment at hand and keep sparks and flame away from the filter.

Lastly, make sure you properly dispose of any contaminated fuel you catch during the replacement process.

Time to Replace Your Spin-on Fuel Filter?

Keeping your spin-on fuel filter clean requires inspecting and replacing it on a regular schedule. The tips in this guide can help you get the most from your filter and ensure you take the replacement task on safely and successfully.

If you’re committing to good spin-on fuel filter maintenance, contact us to talk with a representative who can help you figure out the best option for your needs. We manufacture best-in-class fuel filter water separators for marine, industrial, agricultural, and recreational industries nationwide. Edited