Changing Fuel Filters: Dt 466 Maintenance Guide

Changing the fuel filter on a DT 466 engine can be a challenging task, but it is a necessary part of routine maintenance to ensure the engine's optimal performance. The process may vary depending on the year and model of your vehicle, but there are some general steps and considerations to keep in mind. In this guide, we will walk you through the process of changing the fuel filter on a DT 466 engine, covering topics such as locating the fuel filter, draining the fuel tank, and priming the fuel system. We will also discuss some common issues that may arise during the process and provide troubleshooting tips to help you get your vehicle back on the road safely.

The location of the primary and secondary fuel filters

For a 1986 DTI-466, the primary and secondary fuel filters are located just ahead of the starter. They are twin screw-on filters.

For a 1998 DT466e, the primary fuel filter is located on the driver's side of the engine. Behind the filter, there is a black plunger/pump to prime the fuel system. Underneath that, there is a plastic housing with a screen inside that catches larger particles from the fuel tank.

For a 2002 DT466, there is a small hand pump primer near the filter that looks like a shotgun shell. This is used to prime the fuel system.

It is important to note that the fuel filters may not be labelled as primary and secondary, and it may be necessary to guess which is which based on their location and appearance. Additionally, there may be a pre-filter or "rock catcher" that should be cleaned or replaced when changing the fuel filters.

How to prime the fuel system

To prime the fuel system of a DT 466 engine, you will need to perform the following steps:

Firstly, identify the location of the hand primer pump. This is usually found near the fuel filter and resembles a shotgun shell. Once located, depress the primer pump repeatedly until it becomes difficult to push further. This action helps to build up pressure in the fuel system and eliminate air bubbles.

Next, locate the schrader valve, which resembles a small tire stem valve and is typically capped. Remove the cap and continue to work the hand primer pump until you no longer see air bubbles in the fuel. You may need to gently turn the plastic part of the valve counter-clockwise by a quarter to half a turn to gain access. Remember to be gentle during this process, as too much force can cause damage. Once complete, turn the plastic part clockwise to reseat it.

If the above steps do not work, you may need to attempt an alternative method. Start by unplugging the injector harness where it passes into the valve cover. Then, crank the engine for a few seconds before bleeding the air off and repeating the process until no more air bubbles appear, similar to bleeding brakes. After ensuring that the fuel is free of air bubbles, plug the harness back in and start the engine. Allow the engine to idle for a few minutes before taking the vehicle for a road test.

Note: If you use the alternative method, you may encounter a check engine light. This can be addressed by clearing the codes or disconnecting the battery for a few minutes.

How to clean the rock catcher

To clean the rock catcher on a DT466 engine, follow these steps:

Firstly, locate the rock catcher. It is a small plastic bowl strainer that is situated just forward of the bulkhead on the left side of the engine. It has a plastic cap on top and sits just before the spin-on fuel filter.

Once you have located the rock catcher, remove the plastic bowl by unscrewing it. Clean the reusable screen with brake cleaner or another suitable solvent, ensuring that it is not damaged. Check the O-ring on the bowl to make sure it is in good condition and creating a tight seal. If the O-ring is damaged, replace it with a new one of the same size.

Next, replace the O-ring on the quick-connect fitting where the fuel line plugs into the filter housing. This O-ring tends to get hammered flat over time, which can cause air to be sucked into the fuel system. A new O-ring should cost around $1-2 at a parts store. If the quick-connect fitting itself is damaged, you may need to replace it. However, if it is still intact, you can simply use a zip tie to keep it snug, reducing the hammering on the O-ring.

Finally, reassemble the rock catcher by screwing the bowl back on tightly. Make sure it is secure to prevent fuel leaks.

By regularly cleaning and maintaining the rock catcher, you can help ensure the proper functioning of your DT466 engine and prevent fuel-related issues.

How to drain water from the fuel/water separator

To drain water from the fuel/water separator of a DT466 engine, you will first need to locate the separator. It is likely to be on the frame rail on the right side of the bus under the hood and will probably be a large Racor filter.

Once you have located the separator, follow these steps:

• Place a container under the separator to catch the water and fuel that will be drained.
• Unscrew the bottom of the separator. On a Racor filter, this will usually be done by unscrewing the cartridge.
• Allow the water and fuel to drain into the container.
• Once the separator is empty, replace the cartridge or clean the existing one with brake cleaner. Ensure that the O-ring on the bowl is in good shape.
• Reattach the separator to the engine.

It is important to drain water from the fuel/water separator regularly to prevent water buildup, which can cause damage to the engine.

How to identify the correct replacement fuel filter

To identify the correct replacement fuel filter for your DT 466 engine, you must first determine the specific model and year of your engine. In the forum posts, users with different DT 466 engine models have shared their experiences changing fuel filters, and the process can vary slightly between models.

For example, the original poster in the School Bus Fleet Magazine forum has a 1986 DTI-466 with twin screw-on filters ahead of the starter, while another user has a 2002 IH 4300 with a DT466 engine that has an upside-down spin-on filter. Identifying the correct replacement fuel filter for your specific engine model is crucial, as using the wrong filter can lead to improper fitment and potential damage.

Once you have identified your engine model and year, you can refer to parts catalogues, either online or from authorized dealers, to find the correct replacement fuel filter part number. Cross-referencing this information with reputable automotive parts retailers will help you source the correct filter for your DT 466 engine. It is important to ensure that you are purchasing a compatible filter, as using an incorrect filter can lead to poor engine performance, fuel contamination, or even engine damage.

Additionally, when purchasing a replacement fuel filter, it is advisable to buy from a reputable source that guarantees the quality and compatibility of the part. This will help ensure that you are installing a properly designed and functioning filter that meets the specifications of your DT 466 engine.

Frequently asked questions