Tech Tip: GM Duramax Diesel Fuel Filter Replacement Problems

Tech Tip: GM Duramax Diesel Fuel Filter Replacement Problems

The following tip applies to all 2001-'06 General Motors trucks equipped with the 6.6L Duramax Diesel engine, RPO LB7 or LLY. There are a couple of issues with the fuel filters on these vehicles. GM has released a revised fuel filter; see TSB 04-06-04-070. The new filter is longer than the original filters used and has a plastic housing.

The following tip applies to all 2001-’06 General Motors trucks equipped with the 6.6L Duramax Diesel engine, RPO LB7 or LLY. There are a couple of issues with the fuel filters on these vehicles. GM has released a revised fuel filter; see TSB 04-06-04-070. The new filter is longer than the original filters used and has a plastic housing.

Note: The increased length does not change the replacement interval for the filter.

Both styles of filters include a rubber grommet located in the top of the filter. When removing an old filter, ensure this rubber grommet comes off at the same time. It’s hard to see in the vehicle and may get stuck on the filter adapter, which will not allow the replacement filter to be installed. The new style filter has a smaller inlet with a different grommet. Comparing the two, you might think you have the wrong filter, but it is correct. See Photo 1.

The other issue with the fuel filter system is that the water-in-fuel (WIF) sensor located at the bottom of the filter is made of plastic and is easily damaged while trying to remove or install it onto the filter. You should always remove the sensor and filter as a unit from the vehicle and then transfer it to the new filter.

Install the WIF sensor to the filter, only tightening it by hand. Tighten it to the point where the sensor sealing gasket just contacts the filter. Use a permanent marker and make an index mark on the sensor and the filter. Then, turn the WIF sensor an additional half turn. Once again, only tighten by hand. Do not use pliers or other tools to tighten the sensor. The replacement fuel filter should include a new seal for the sensor.

If the WIF sensor will not seal properly to the new filter, it may have been damaged during a previous filter change and you will experience a leak situation. If the WIF sensor will not tighten correctly, it will need to be replaced.

Courtesy of Nick Taylor, administrator, Mitchell 1 OnDemand5.com.

For more information on Mitchell 1 products and services, automotive professionals can log onto the company’s website at www.mitchell1.com.

You May Also Like

CITGO Enters EV Space with Pilot Program Launch

The CITGO location on 11 Mile Road in Michigan now offers both regular transportation fuel and EV charging stations.

CITGO Petroleum Corporation, along with marketer Folk Oil Company, recently launched an electric vehicle (EV) charging pilot program they said is designed to meet the needs of EV drivers in Battle Creek, Mich. The CITGO location at 15551 11 Mile Road now offers both regular transportation fuel and EV charging stations. For added consumer convenience, EV chargers include both Charging System (CCS) and the North American Charging Standard (NACS) plugs, the companies said.

TS Toolbox Guide February 2024

Here’s a look at some of the core feature and modern frills to consider when it’s time to move into a new office.

toolbox guide illustartion
Stellantis Increasing Production of Electric Drive Modules

The company will add EDM production in Szentgotthard, Hungary, targeted to begin in late 2026.

Embracing Cutting-Edge Solutions the Industry has to Offer

Embracing cutting-edge solutions is strategic and imperative for technicians navigating the constantly changing landscape of automotive maintenance and repair.

Nadine Battah
Tool Time Podcast: Clore Automotive

Jim O’Hara from Clore Automotive joins Nadine Battah and Eric Garbe.

Other Posts

TechShop, ShopOwner Offer $50 For Good Guesses

Guess the Tool for a chance at cold hard cash!

GM, Honda Begin Volume Production of Fuel Cell Systems

GM and Honda will produce fuel cells that will be two-thirds less expensive compared to Honda’s 2019 Clarity fuel cell.

Toyota Bringing Battery EV Production to Kentucky

It will invest $1.3 billion at its flagship Kentucky facility for future electrification efforts, including assembly of an all-new, three-row battery electric SUV for the U.S. market.

Repairify Announces Executive Leadership Changes

The company has named Craig Edmonds as president of asTech among other executive appointments.