Changing the Fuel Filter on my truck

[lmholmes11]

Hello all, i have changed the fuel filter on my old truck which was gas many of times. Could anyone tell me if a diesel truck is any different? And if so what are the proper procedures? Thanks!

[DmaxMaverick]

It's very different. Under the hood at the passenger side of the engine (US passenger side), is the filter assy. The filter spins on/off like an oil filter, but the gasket is an O-ring on the perimeter and a smaller grommet on the inside. Be sure to get the old rubber grommet out, because they don't always come out with the filter, and 2 won't fit. Use some bearing or dielectric grease in the O-ring groove to help it stay in place. At the bottom of the filter is the WIF sensor (Water In Fuel) which needs to be disconnected at the connector during the R/R. Be careful where the wires attach to the sensor, as they can break if rough handled. A strap wrench is best for removal. Installation should usually be OK hand tight, but may need a little persuasion with the wrench to stop an air leak (the fuel system is suction from the tank to the high pressure pump). Access to the filter can be had by removing the battery and/or the fender liner. I do neither, but the fender liner is the best route, IMO. When done, the filter needs to be bled by pumping the primer pump on the top of the filter assy. Pump it until you can't, which can be a lot of pumping. 100 or more strokes isn't uncommon. If it starts, then dies, pump it again. Repeat as necessary until it stays running. If it doesn't keep running after a few priming attempts, the filter is leaking air. Verify the O-ring is properly seated and try again after using the strap wrench to tighten it. Also, do not prefill the filter with fuel, like you might with an oil filter. You risk contaminating the system. Just prime it after it's installed. There are wrenches available for the WIF sensor, and they're nice. I don't have one. I've used a water pump plier (carefully) for years on the original sensor. I should have a wrench, but don't.

Try a search of the forum for a bunch more info if you need it. I've probably left out some important or convenient info, so a search probably won't hurt in any case.

[lmholmes11]

Ok thanks, I really appreciate the help. Im glad i asked!

[Dakster]

You forgot the most important difference...... The price - and also the frequency you should change it. :)

The first time you change it, I would remove the fender liner. You can sit on a step stool comfortably and see exactly what, where, and how you need to change it. (I'll actually remove the fender liner everytime... But that is just me, it won't be that often as I only drive about 500 miles a month)

[Mark Rinker]

There is pleny of room for most hands to get the LB7 ('01-'04) filters off from underhood. I use mechanix gloves and simply hand tighten each time, no wrench required unless they get stuck on and can be freed up.

My LLY/LBZ (early '06) is much easier to address through the fenderwell, however. The AC line routing makes it impossible to get a good grip, or alignment on the filter.

[Dakster]

I've only had first "hand" experience on my LMM... Sounds like earlier year DMAX's were easier/quicker.

[DmaxMaverick]

I've only had first "hand" experience on my LMM... Sounds like earlier year DMAX's were easier/quicker.

Yes, they are. A lot less "stuff" in the way.