Replacing Fuel Filter: First Gen Cummins Diy Guide

Changing the fuel filter on a first-gen Cummins is a relatively simple task that can be completed in a few steps. First, you need to drain the fuel by opening the water drain valve located at the bottom of the filter housing. You can attach a hose to this valve to direct the drained fuel into a catch pan or bucket. Once the fuel is drained, you can remove the filter housing. For a 5.9L engine, simply remove the cap and lift out the filter. On a 6.7L engine, you'll need to unplug the water-in-fuel sensor before lowering the canister and filter out.

When installing the new filter, make sure to lubricate the canister O-ring and replace it if necessary. Prime the system by cycling the key without starting the engine 10 to 20 times. This will allow the low-pressure fuel pump to fill the new filter and purge the system of air.

Drain the fuel filter housing

To drain the fuel filter housing of a first-gen Cummins, you'll need to locate the water drain valve at the bottom of the filter housing. This is sometimes referred to as the water separator valve or the water-in-fuel sensor.

Attach a hose to the nipple or drain tube of the valve and place the other end in a catch pan or bucket. Open the valve to start draining the fuel.

Some people recommend extending the hose to reach a bucket to avoid mess. You can also open the valve for a few seconds before removing the filter canister to avoid spillage.

Once the fuel has been drained, close the valve and remove the hose from the housing.

Remove the old filter

To remove the old filter, first, drain the fuel from the canister. Locate the water drain valve at the bottom of the filter housing and attach a hose to the nipple. Place the other end of the hose in a bucket or catch pan and open the valve to drain the fuel.

Next, you will need to remove the canister bottom to access the old filter. Loosen the nut on top of the filter housing until the bottom housing is free. Be careful not to spill any residual fuel. Once the bottom housing is removed, carefully lower and remove the old filter from the top housing. Take note of the location of the o-rings and remove them from the old filter.

Now you are ready to install the new filter.

Clean the inside of the housing

To clean the inside of the housing of your first-gen Cummins, you'll first need to remove the fuel filter. Here's a step-by-step guide:

• Place a drip pan or bucket underneath the filter to catch any spills.
• Drain the fuel from the canister by opening the water drain valve or separator valve. You can attach a hose to the nipple and route it to your catch pan.
• Once the fuel is drained, remove the water-in-fuel (WIF) sensor wiring connector.
• Loosen and remove the cap or lid of the filter housing. You may need a 1 1/8" socket for this step. Be careful not to twist the housing too much, as you could break the fuel heater wires or unscrew the fuel heater.
• With the cap removed, carefully lower the filter housing and remove the old filter, noting the position of the O-rings.
• Now you can clean the inside of the housing. Use a clean, lint-free cloth to wipe away any debris or residue. Pay close attention to the O-ring grooves and make sure they are free of dirt or gunk.
• Before installing the new filter, lubricate the new O-rings with a thin coat of oil or diesel fuel.
• Reinstall the new filter and O-rings, making sure to align the bottom housing with the top housing correctly.
• Tighten the housing cap to the specified torque (around 15-20 ft-lbs or 24 Ft. Lbs, depending on your model).
• Reconnect the drain tube and WIF sensor harness.
• To prime the filter and remove any air, cycle the ignition key without starting the engine 10 to 20 times. This will run the electric lift pump and fill the new filter with fuel.
• Start the engine and check for any leaks.

Remember to wear appropriate safety gear, such as gloves and eye protection, when performing this task.

Install the new filter

Now that you've drained the fuel and removed the old filter, it's time to install the new one.

First, you'll want to fill the new filter with clean fuel. This will make it easier to install and prevent air from getting trapped in the system. You can use a funnel with a long tube to fill the new filter, or you may find it easier to fill the canister with fuel and then insert the new filter.

Next, apply a thin coat of oil or lubricant to the seals of the new filter. This will help to create a tight seal and prevent leaks.

Now, carefully screw the new filter into the housing. Be careful not to overtighten it, as the housing is made of plastic and can strip or break if too much force is applied. Hand-tightening should be sufficient, with perhaps a quick snug down with a ratchet.

Once the new filter is in place, reconnect the water-in-fuel (WIF) sensor wiring connector and any other disconnected components. Make sure to properly dispose of the old filter and any drained fuel.

Finally, prime the new filter by cycling the key in the ignition 10 to 20 times without starting the engine. This will allow the low-pressure fuel pump to fill the new filter and purge the system of any remaining air.

Now, start the engine and check for leaks. Your new fuel filter is now installed and you're ready to hit the road!

Prime the fuel system

To prime the fuel system of a first-gen Cummins, you need to cycle the key without starting the truck 10 to 20 times. This will allow the vehicle's low-pressure fuel pump to fill the new filters with fuel and purge the system of air.

• Open the water drain valve on the fuel filter canister and drain a small amount of fuel. This will prevent fuel from spilling when you remove the filter.
• Close the drain valve and remove the drain hose from the housing.
• Remove the water-in-fuel (WIF) sensor wiring connector.
• Place a small drip pan or a catch can under the filter to catch any remaining fuel.
• Loosen the nut on the top of the filter housing until the bottom housing is free. Hold the bottom of the filter housing to prevent it from dropping and spilling fuel.
• Lower and remove the bottom housing from the top housing.
• Remove the filter element from the housing, paying attention to the location of the O-rings.
• Install the new filter element and replace the O-rings. Lubricate the O-rings before installing.
• Align the bottom housing with the top housing and replace the nut. Tighten the nut to the specified torque (refer to your vehicle's repair manual for the correct torque value).
• Connect the drain tube and WIF sensor harness.
• Prime the filter by turning the ignition to "Start" briefly, then back to "Run". This will activate the electric lift pump for about 20 seconds, filling the filter with fuel.
• Repeat the priming process once or twice more, then try to start the engine. If it doesn't start after several attempts, repeat the priming procedure.
• Once the engine starts, let it run for a few minutes and check for any leaks.

It is important to note that priming the fuel system is a crucial step after changing the fuel filter. It ensures that the new filter is filled with fuel and any air is purged from the system, allowing the engine to start and run smoothly.

Frequently asked questions