It was recently time to change the fuel filter on my LBZ, and after seeing how many fuel filter replacement related questions are often asked in the Maintenance forum I figured I'd make a little picture guide to help out.

The fuel filter on the duramax is located on the passenger side of the motor, slightly hidden under the air intake.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02635.jpg

The filter can be accessed and removed from the top of the motor, but I find it far easier to remove the passenger inner fender to access the filter.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02636.jpg

The inner fender is held in with a series of press in fasteners, and are easily removed by popping the center section of the fastener up allowing the entire fastener to be pulled out.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02638.jpg

With the inner fender removed you will clearly be able to see and access the fuel filter as it hangs from its mount. Before you remove the filter you must disconnect the electrical connection for the filters sensor. The sensor itself is on the bottom of the filter and is made of plastic, so be gentle with it. The electrical connection has a small locking tab, circled below, which must be pressed in order to unplug the connector.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02642.jpg

With the connector unplugged you can now un-screw the fuel filter from its mount. This is often easier said than done, as the filter typically gets stuck on fairly tight, a filter wrench might be required to loosen the filter. The filter, and its mount, are full of diesel fuel so put a catch pan down to collect all the fuel which will spill out.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02643.jpg

With the filter removed you next have to remove the sensor located on the bottom of the filter. As mentioned earlier, the sensor is plastic so be gentle with it. I have a large enough wrench to use on the sensor, but have used sliding pliers to remove it. PPE sells a specific sensor wrench for this as well. http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=215

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02644.jpg

Once the sensor is removed, install the new rubber O-ring supplied with your new filter onto the sensor. Coat the ring in diesel fuel to help it seal better, then install the sensor onto your new fuel filter. Tighten the sensor as tightly as you can by hand, then give it another 1/2 turn with your wrench/pliers.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02645.jpg

The other end (top end) of your new fuel filter also needs an O-ring to help it seal. Coat this O-ring in diesel fuel also to help it seal. Depending on your brand of filter, it might already have an O-ring installed on the filter, but if its like my filter you have to install the supplied O-ring yourself. Make sure the O-ring fits into its recessed groove all the way around the filter to prevent any leaks.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02646.jpg

Installation is the opposite of removal, screw the new fuel filter into its housing and reconnect the electrical connection for the sensor. I like to install the filter as tightly as I can by hand without using any filter wrench, this ensures it wont be as hard to remove next time. Dont reinstall your inner fender yet.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02647.jpg

Next the fuel filter needs to be primed. On top of the fuel filters housing there is a small plastic bleeder screw, circled below. Gently loosen this screw, its plastic so dont damage it. You dont need to entirely remove the screw, just loosen it enough to let the air out.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02648.jpg

With the bleeder screw loosened start pressing the priming plunger to begin filling your new fuel filter. Keep cycling the plunger until fuel starts spitting out of the bleeder screw, then tighten the bleeder screw back down. People have always told me that it takes millions of pumps on the plunger to get the new fuel filter primed, but every time I do it I only need 3 or 4 pumps before the jobs done...I guess its something me and my truck have in common.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02649.jpg

Once the fuel filter is primed you can start your truck up. This is where my earlier recommendation of leaving your inner fender removed comes in handy, as while your truck is currently running you can visually check your fuel filter for any leaks. If no leaks are present you can reinstall your inner fender.

Last but not least, dont forget to reset your fuel filter life monitor if your truck is equipped with one. Congratulations on replacing your fuel filter.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02650.jpg

If anyones wondering what I was using to remove the inner fender, its a door panel tool that I bought from my local Snap-On distributor.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02637.jpg

Another thing to keep in mind is that while your inner fender is removed this is a perfect time to wash out all the dirt and mud that builds up behind it. As well as washing the inner fender itself.

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02639.jpg

http://img.photobucket.com/albums/v108/shark_37/Pictures%20From%20Work/DSC02640.jpg

I hope this all helps, if anyone has any questions or concerns feel free to ask.

I just did this last week on an LMM. 10k miles on the Napa Gold 3960. Quite dirty in my opinion.

106812

I'd say thats a good thing, I'd rather have all that dirty stuff caught up in my filter rather than going through my engine.

Oh, not complaining on the fact that it caught it, just that 10k may be a too long of a change interval for me (btw, it took about 3 months to run that 10k miles).

The DIC stated I was at 55% fuel filter life.

I thought the pic might add to the thread as well (same filter).

Intall a door while you are at it from this DP vendor:

CLASSIC
http://madjacksynthetics.com/Chevy/GMC-Duramax/Duramax-Fuel-System-Related-Parts-Filters/Duramax-LB7/LLY/LBZ-Fuel-Filter-Access-Door/prod_59.html

LMM
http://madjacksynthetics.com/Chevy/GMC-Duramax/Duramax-Fuel-System-Related-Parts-Filters/Duramax-LMM-Fuel-Filter-Access-Door/prod_58.html

I sure like doing fuel filter changes with the access panel..... I go every 15K per the Duramax supplement manual.

;)

Actually, I did that as well! ...from that vendor! Very pleased.

(also did the fumoto valve, oil change, and air filter.)