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  • Tips And Tricks For A Quick and Easy Filter Change - Fuel Filter Basics

Tips And Tricks For A Quick and Easy Filter Change - Fuel Filter Basics

Don’t let this happen to you!

Jun 4, 2014
Photographers: The Manufacturers
Clean fuel is key to a healthy diesel engine. Fuel filter replacement is one of the major maintenance items that is often neglected or overlooked entirely. Diesel fuel filters also serve a dual purpose, filtering out both debris and water. When filters get clogged, they can allow water to bypass them, contaminating the truck’s injection system. Waiting until the filter element is completely plugged before changing can also lead to fuel starvation that will not only cause performance loss, but also potentially damage injectors, injection pumps, and lift pumps. The bottom line is: Bad things happen when filters are left unchanged.
The good news is, however, changing a fuel filter is something anybody can do. All that’s needed are the new filter (or filters if you own an ’03 or newer Ford), a catch pan or bucket, and a couple of basic handtools. This month’s basic training lesson is not meant to be an all-inclusive guide to changing your specific filter, rather a primer demonstrating the ease and basic procedure for most trucks. Be sure to consult your owner’s manual for your truck’s specific filter change intervals (typically around 15,000 miles) and filter part numbers. Diesel fuel filters aren’t always cheap, but we suggest purchasing factory replacement units, as some of the more inexpensive alternatives don’t always provide the protection sensitive high-pressure fuel systems require.
After you’ve read this and decided it’s time to change your fuel filter, a great resource for step-by-step instructions for the first- timer is the Internet. While it may seem obvious to some, make-specific forums, Google, and YouTube are chock-full of how-to stories and instructional videos. With their help there is no reason to shy away from performing a filter change at home, saving a costly trip to the dealer and keeping your fuel system in tip-top shape.
Photo 2/9   |   Both 5.9L and 6.7L Cummins fuel filters are located on the driver side of the engine, below the intake manifold.
Cummins
On Cummins engines, the fuel filter type and style has changed slightly over the years, so for our purposes we’re going to describe those found on the common-rail engines. Both 5.9L and 6.7L filters are located on the driver side of the engine, below the intake manifold. The major difference lies in how they are oriented, with the 5.9L filter being accessible from the topside of the engine and the 6.7L from under the truck.
To change the filter, the first step is draining the fuel. Located on the bottom of the filter housing is a water drain valve. Attach a hose to this nipple and route it to a catch pan, then open the valve and drain the fuel. With the filter drained you can now remove the housing. On the 5.9L, the cap is removed and the filter lifts up and out, however, on the 6.7L you first need to unplug the water-in-fuel sensor before lowering the canister and filter out through the bottom of the vehicle. The filters are reinstalled in the reverse order; make sure to replace and lubricate the canister O-ring. To prime the system, cycle the key without starting the truck 10 to 20 times.
Photo 3/9   |   All the Cummins-equipped Rams use a cartridge-style filter, with the 5.9L being accessible from the top. A 1 1⁄8-inch socket is used to remove the filter cap.

Duramax
The Duramax fuel filter is located on the passenger side of the engine compartment, near the firewall and next to the battery. Due to its location, guys with larger hands need to think skinny in order to get a grip on the filter. Removing the plastic fenderwell liner is the easiest way to expose the filter, since it is only held on with about 14 plastic snap fasteners and takes mere minutes to remove. Making the Duramax fuel filter unique is its integrated water-in-fuel sensor, which also houses the water drain petcock. This sensor needs to be unplugged from the vehicle’s wire harness before spinning the filter off, and once removed, a special wrench is required to remove and install the sensor.
Replacement filters will provide two new O-ring seals: one for the sensor bulkhead and one for the filter’s sealing surface, both of which should be lubricated with a petroleum-based lubricant before being installed. Once the new filter is attached to the truck, it’s time to prime the filter. On the Duramax, priming is done by first opening the relief valve (accomplished with a ½-inch nut driver or flat-head screwdriver) and then manually depressing the primer pump located on top of the filter housing. This process takes a bit of time, so patience is key. Once all the air is bled from the filter, the relief valve should be closed and the process is complete.
Photo 4/9   |   This is the Duramax fuel filter’s factory location. As you can see, it can be tough to reach from the top.
Photo 5/9   |   While some people resort to pliers to remove the fuel-in-water sensor, there’s a special tool that makes the job much easier and doesn’t risk destroying the delicate plastic.
Photo 6/9   |   On this relocated filter you can clearly see the relief valve and the primer pump.

Power Stroke
The Power Stroke family of engines is the most unique when it comes to not only fuel filter type and placement, but also quantity. While the Duramax utilizes a single sealed spin-on-type filter and Cummins uses a single cartridge, Fords equipped with 6.0L, 6.4L, and 6.7L engines receive two cartridge filters (7.3L engines use a single cartridge.) The primary filter is located along the driver framerail at about the midpoint of the chassis, and brake lines and wire harnesses can obstruct depending on year. On ’03 and newer models, the secondary filter is located on top of the engine.
Thankfully, changing the filters is a relatively straightforward task. The first step is to drain the filter using the water drain valve. While the procedure is the same, the actual drain valve is different on each engine model. With the fuel drained, the canister cap can be removed and the new filter installed. Make sure to replace the old O-rings with the ones provided. On the 6.0L and 6.4L engines, the secondary filter is changed in much the same way. Simply remove the plastic cap and replace the filter element and O-ring.
As a departure from the previous cartridge-style secondary filter, the 6.7L uses a sealed cartridge, which is replaced as a unit. Replacement requires a setscrew to be loosened and the two quick-disconnect fuel lines to be removed. With those steps complete, the unit simply lifts out for disposal. For a quick way to know if the filter has ever been changed, look for a third nipple, which is present only on the original factory filter.
Priming the fuel system simply requires the key to be cycled 10 to 20 times without starting the engine. This will allow the vehicle’s low-pressure fuel pump to fill the new filters with fuel and purge the system of air.
Photo 7/9   |   If you’re lucky enough to own a 6.0L, 6.4L, or 6.7L Power Stroke, you’ll find a secondary fuel filter, similar to this one, under the hood.
Photo 8/9   |   Seen here is the primary fuel filter on a 6.0L-equipped F-550 four-wheel drive. Mounted near mid-chassis on the driver side, this truck’s filter is partially obscured by the front driveshaft. Also note the water drain is a plug, which is removable with a hex bit.
Photo 9/9   |   On 6.4L-equipped trucks, the water drain valve became more user friendly—and it got even easier on 6.7Ls.

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