Duramax Fuel Filter Replacement
 

How to replace a Fuel Filter on a Duramax.

To get you familiar with the Fuel Filter it is located underneath the hood near the firewall on the passenger side on the engine.

Attachment 58011

The tools needed to change out the d-max fuel filter using the side approach are a panel clip remover, a Water In Fuel sensor wrench (or channel locks), a 1/2 inch Nut driver, and I use 2-stroke oil to lube up the o-rings.

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Starting off pop the hood, and then grab a seat and sit by your passenger side tire looking at the fender well.

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Now using a the panel clip remover, you want to remove the pins that are holding the inner fender well liner to the truck. (can be easily done with the right tool, I have seen one of these at oriellys)

Attachment 58014

Now with all the pins remove and all the wire harnesses pulled out of the liner you can set the liner aside.

Now you can have a good view of the Fuel Filter from where the passenger side.

Attachment 58015

Now disconnect the WIF connector and let it hang.

Attachment 58016 Attachment 58017

Now you can unscrew the fuel filter and remove it. you might be able to do it with your hands if you are strong enough, if not u can use a strap wrench which can be found at any auto parts store.

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Duramax Fuel Filter Replacement cont.....
 

With the Fuel Filter removed dispose the contents inside the filter properly.

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Now using a WIF wrench (or channel locks) remove the WIF sensor.

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The new filter should come with new o-rings so make sure that you remove and discard the old o-rings.

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Now Lube up the Big o-ring and the outer edge of the filter where the o-ring is going to be places with some 2-stroke oil, and don't be shy about using it either.

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And don't forget to replace the little o-ring on the WIF sensor. again lubing it up also.

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With the Fuel Filter and WIF sensor back together it is now ready to go back into the truck.

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This part can be a little frustrating because it is an awkward position and its hard to get the filter threaded on there. Be patient and it will thread its way on there. And Tighten down the Filter as recommended (1/3 to 1/2 turn after the seal has made contact.)

Attachment 58009

Now Go back to the to the engine and look at it from under the hood and you will see the Filter pump and bleeder screw.

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Loosen up the Bleeder screw with a 1/2 inch nut driver(do not take out all the way, just enough to let air out)

Attachment 58001

Now with the bleeder screw loosened you can begin priming the fuel filter, this will take about half a million pumps so be patient.

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You will hear air coming out the screw and eventually Diesel Fuel will come out, and when that does press down the primer pump and hold it then with the other hand tighten down the bleeder screw(warning do not over tighten). And after tightening down the screw keep pumping the primer until it gets very hard to pump, it will be almost impossible to pump anymore after that.





Presto Change-o you fuel filter has been changed and you can wrestle back on the inner fender liner and start the truck. :U:

Very Nice thanks !!!!!

sticky?

I change my filters in less than 10 minutes without removing anything from the truck. No need to remove the fender liner.

This can be done from under the hood as well without taking out the inner fender lining. Which ever way you do it works.

Yeah you can change it from the underneath the hood going from the top, but this is the way i change mine, it is easier for me, its hard for me to reach down under there and do all that stuff, i have only full rotation in my right arm, the lefty is kinda bent :ouch:


Your more than welcome to post pics of how u change it from the top.:pca1:

ya especially if your water in fuel sensors wire has been broke off don't have to worry about reconnecting but hey good job (for a lb7 guy ) hahaha just had to

I would try to get some pics but I just replaced mine last month and don't feel like wasting fuel for some pictures:w2:. I would say do which ever one is easier for you to do. I prefer under the hood and others prefer going through the wheel well. As long as it gets changed thats all that matters. Just be careful when tightening down the bleeder screw that you don't break it! The truck will not start and it is a Dealer only part. Not cheap!!!!!!

Oh no Danno...that's a good write up and most will do it that way. To change it the way I do you have to have two hands that work really well and some dexterity. :)

I mostly did it the way i did for people who want to try and do it them self for the first time and give them a lot of pictures and make it as easy as possible to remove he filter without bumping into anything and breaking it...



and not have to wait 2 hours for the dealer to do it :mad3:

Not to mention the outrageous cost. :madd:

i believe merchant automotive sells a metal replacement for the bleeder screw, and u can use just a regular flat head screw driver

the bleed screw cost about $16 and i have a spare already i broke on off already never use a ratchet to tighten it :baby:

1/2 inch or 13mm nut driver works perfectly on them, just be gentle. ima see if i can find a torque spec on it....



nope there isn't one, they don't even tell you to bleed the air out after replacing the filter in the service manual

I tighten my stock unit with my fingers and I've never had a leak.:yeah:

me neither

But your running the risk of breaking yours. :dd:

I never touch the bleeder screw. Just prime it, start it, it'll die, repump, restart, all is good. Never risk breaking the screw when it's never touched.

It is true merchant Automotive has the metal ones. But if you break it that day and the dealer is closed (Like a Sunday like mine), and you don't have a spare your SOL. Also something to think about. I know they have metal ones out there but if GM wanted a metal one on the truck thats what they would have put on it. For some reason the engineers wanted the plastic in there. Not sure on a really good reason but there has to be a pretty good reason(I hope).

Well...coming from an Engineer...it was one of the dumbest things they could have done. :pca1: Actually, its typically the MBA's NOT the Engineers that make the dumb decisions. :madd:

You can get a bolt that will fix there to replace the bleeder screw and any hardware store. I don't remember the size off hand, but I have posted it on DP before. When I have more time I'll or some else can look it up.

Hadn't found it on Merchant's site. Found this one, though.

Shop

thats the same style merchant has

have u found the bolt yet?

Good write-up, Danno. I've done these both ways and prefer to remove the fender liner. It just makes it easier to get to things and I don't get my forearms wedged into places.

Yep, its kinds hard to do it form the top with big masculine arms, they get stuck

very informative i haven't had the joy of changing mine yet.

any recomendations on a good fuel filter to use something better than stock?

ur pretty much stuck using the ac-delco or macthing stock filter.

But there plenty of aftermarket fuel filter addons u can add :U:

i found an afe fuel filter for my lb-7. has any one tried one? any difference than stock?

whats the pice dirrerence compared to stock?

it is about $10 cheaper than the stock one at my dealership but i don't care about the price.

i just want the best for my truck. it helps me make my money so i want to keep it that way. my old 94 gm has 330k miles on it and i haven't had to do much more than reg maintenance on it. because of how i maintain my truck. and i want this on to be just like it.

u know how many microns it filters down to?

Does anyone fill the filter up with fuel before screwing it back on? Wondering if this would save time and pumping??

i dont, cause i have a lift pump i just turn it on to prime the filter after i replace it.

but yeah it would save time and pumping

dont forget....if you are planning on putting a pyro in...a good time to do it is when you change the filter, that is if you remove the liner.:U:

Duramax Fuel Filter Change
 

Just wanted to say that the pictures and instructions were great, I changed the filter and had no problems.

Yeah, Danny is the man! :c:
I do it from the top without removing the liner. Can change it in about 20-30 minutes now, it's super easy. I use a filter wrench to turn the last 1/2 turn on the filter to make it's tight.

in the 2008 series, it is best done using the methods described, and removing the inner fender well liner, otherwise, you can remove it from the top under the hood, but, you will need to dismount the primer pump from the engine block to give enough space to remove the filter and leave it dismounted until you've installed the replacement filter. Some engineer decided it would be a good idea to make it impossible to get the filter out once it's been unscrewed, and in the owners manual it says to remove the inner fender well liner clips, but only the ones on the rear of the fender.