# Any tips or suggestions for fuel filter replacement?



## Barry Allen (Apr 18, 2018)

I've bought the AC Delco fuel filter kit ($5 mail-in rebate on that). In the next 1,000 miles I'm ready to replace it.

Does anyone here have tips to make the job easy?

Is it worth purchasing the billet aluminium replacement housing for this car?






Amazon.com: H&S Motorsports 2017-2018 GM Duramax 6.6L L5P Billet Fuel Filter Housing: Automotive


Buy H&S Motorsports 2017-2018 GM Duramax 6.6L L5P Billet Fuel Filter Housing: Fuel Filters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



www.amazon.com


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## MP81 (Jul 20, 2015)

I can't see why that would be necessary - the plastic one has worked just fine, thus far.


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## Barry Allen (Apr 18, 2018)

MP81 said:


> I can't see why that would be necessary - the plastic one has worked just fine, thus far.


Road debris. I'd hate to see a piece of cement or other debris kicked up to where it cracks the factory filter housing. Billet aluminium might take a better hit without fracture.


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## MP81 (Jul 20, 2015)

Is the 2nd gen not covered by an aeroshield? The 1st gens has the aeroshield under it, plus the added benefit of being tucked up a good bit anyway, too.


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## mkohan (Dec 19, 2015)

When changing my fuel filter on a GEN 1 I found the following to help. Use correct size socket with a long handle racket and make sure your are that everything is square as you are turning. Good luck.


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## cdccjohnson (Apr 10, 2018)

I had to use a impact gun to get it off the first time. When I tried just a rachet, it just turned the housing out of its mounting bracket. Even with the impact gun, it took a bit and didnt fly off.


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> I've bought the AC Delco fuel filter kit ($5 mail-in rebate on that). In the next 1,000 miles I'm ready to replace it.
> 
> Does anyone here have tips to make the job easy?
> 
> ...


I am absolutely looking at that billet cap, there is another one that is about $70 also, a bit expensive.. but the reason is not about looks or even protection from road damage. The plastic on these seems to swell, and on my Gen 1 on the last change it was so tight, it was IMPOSSIBLE to remove while on the vehicle. I had to remove the entire housing, clamp it in a vise, carefully I might add, and use a strap wrench to get it off, and it was tight even after it began to twist off, I was able to get it back together, still tight, but used a bit of teflon grease hoping it won't be such a pain next time, and found a new housing for a decent price just in case. I do think the problem could be eliminated with that billet cap, and as my next one is coming due, I have that on a watch on an amazon list.. I wish it wasn't so expensive, but over the life of the car and multiple filter changes.. I'm thinking it is worth it.


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## MRO1791 (Sep 2, 2016)

Found it, was $86 when added to my list, now $79, the also have a kit with aftermarket filter for $80. I used one of those filters, and could not see any problem with the quality. Amazon.com: iFJF 134001 Fuel Filter Housing Cap for 2017+ GM Duramax 6.6L L5P Billet Aluminum with Drain Plug (Silver): Automotive


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## MRO1791 (Sep 2, 2016)

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Barry Allen said:


> I've bought the AC Delco fuel filter kit ($5 mail-in rebate on that). In the next 1,000 miles I'm ready to replace it.
> 
> Does anyone here have tips to make the job easy?
> 
> ...


As to tips, I learned the hard way.. if it is just not coming off with hand force, be careful, as that housing is plastic, mounted to the side of the plastic fuel tank, If you turn too hard, it will pop it off it's plastic mount.. at that point I tried a strap wrench on the housing side as is was dangling from the fuel lines.. BIG mistake, do NOT do that. Not only did I nearly destroy the housing (small crack in the mount I was able to plastic weld/fix off the car), I ended up kinking the plastic fuel lines, but they appeared to be OK, but it could have busted a fuel line, and the replacements are not cheap, and making them requires special tools, also not cheap. 

Also, it seems that the thing drains forever, and ever.. It might be best to try this when you have less than 1/2 a tank, because I think my difficulty draining was a siphon effect from the nearly full fuel tank. I eventually just put a large catch pan and went at it, but it gets messy real fast, especially with the car on a ramp and limited room to work. 

If you have any problem spinning off that cap, consider removal of the entire housing right away. The lines are a quick connect type, and not difficult to disconnect, have something to catch the fuel, and then there is one electrical connector. It is far easier and safer to remove that cap in a vise if it not coming under the car. 

This my lesson learned the hard way, and that was not the first time on these cars, rather like the 3rd time. The first two times went pretty easy, minus the seemingly perpetual drain action. I think the plastic swells slowly over time, which explains the difficulty on the last effort.


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## MP81 (Jul 20, 2015)

There's like...a solid 3/4 quart of diesel that will come out, at least in the Gen 1 cars. I just yank the bandaid off and just have it drain "automatically" as/after I remove the housing.


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> Also, it seems that the thing drains forever, and ever..


I've got a good, clean catch pan so I can funnel the fuel back into the tank when I'm finished.


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> a kit with aftermarket filter for $80.


I saw that. I'm not using anything other than the OEM fuel filter because some reviews of the aftermarket state that it's not the same dimensions/size/fit, etc.

I'd love to switch to a CAT filter to have a setup where it's an easy spin-on filter to change (and 2 micron filtration), but that big CAT filter won't fit under the car so unless it were relocated somewhere it won't work.


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> I saw that. I'm not using anything other than the OEM fuel filter because some reviews of the aftermarket state that it's not the same dimensions/size/fit, etc.
> 
> I'd love to switch to a CAT filter to have a setup where it's an easy spin-on filter to change (and 2 micron filtration), but that big CAT filter won't fit under the car so unless it were relocated somewhere it won't work.


I did a 2 micron filter on my truck, lots of room there. In any case you should keep the existing, as it also contains a fuel heater and ability to separate water. The CAT filter won't do wither of those, but would be a great second polish filter.. assuming even possible to find space, best option might be under hood, it's not as tight as the Gen 1, but will still be a challenge I'm sure. 
In the picture, the 2 white filters are for fuel, the orange is transmission fluid. The cooler on the left is a system I came up with to cool the transmission on my truck, its a manual, but heat has been a known weakness, so I added a pump, filter and cooler to sort that out. The first filter is actually a factory optional add on (it has a heater, water and fuel sensor, and is a separator 10 micron, I call it a pre-filter), the second Donaldson I added for the 2 micron rating. I also monitor inlet and outlet pressure so it can be changed by actual condition of the filter. There certainly is no room for anything like this on the Cruze!


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> I did a 2 micron filter on my truck, lots of room there. In any case you should keep the existing, as it also contains a fuel heater and ability to separate water.


I don't care about a fuel heater. I buy good quality fuel and I use a winter additive, and that's good enough.

I have yet to see the stock water separator on my car do anything. In 40,000 miles I haven't seen any "water in fuel" messages on the instrument cluster, so it must not be an issue with where I am purchasing fuel. When I use the Power Service winter additive there is a portion of that package that keeps water from "dropping out" so that's good enough for winter use.


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## BaggerJack (Dec 24, 2019)

Are you guys saying the fuel filter cap for a Duramax 6.6L L5P is the same cap for the Gen2 Cruze diesels?


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## MRO1791 (Sep 2, 2016)

BaggerJack said:


> Are you guys saying the fuel filter cap for a Duramax 6.6L L5P is the same cap for the Gen2 Cruze diesels?


As far as I can tell it is. It's the same filter for sure, and only makes sense it would be the same housing. 

Sent from my Moto G (5) Plus using Tapatalk


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> I don't care about a fuel heater. I buy good quality fuel and I use a winter additive, and that's good enough.
> 
> I have yet to see the stock water separator on my car do anything. In 40,000 miles I haven't seen any "water in fuel" messages on the instrument cluster, so it must not be an issue with where I am purchasing fuel. When I use the Power Service winter additive there is a portion of that package that keeps water from "dropping out" so that's good enough for winter use.


Understand, however I should point out that in normal operation you shouldn't see any water. The reason it's there is to protect from abnormal conditions. I think it's impossible to know for sure that you won't get some water in a fill up, even stations you normally use could get a bad fill it have a leak and get run off or ground water in their tanks. I certainly would caution against removal of that capability. As mechanical engineer with an MBA I know 2 important things about why GM put that on the car. 1) the engineers thought it was important, 2) the business guys were willing to take a hit on possible profit to pay for it. Those two things make me pretty certain it's something you should be very cautious about removing. 

Sent from my Moto G (5) Plus using Tapatalk


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> As mechanical engineer with an MBA I know 2 important things about why GM put that on the car. 1) the engineers thought it was important, 2) the business guys were willing to take a hit on possible profit to pay for it. Those two things make me pretty certain it's something you should be very cautious about removing.


GM never put a water separator on my father's Oldsmobile Delta 88 with the LF9 engine, and look how that turned out. Oh, wait a minute...


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> GM never put a water separator on my father's Oldsmobile Delta 88 with the LF9 engine, and look how that turned out. Oh, wait a minute...


That was a great example of pushing the numbers over any sound engineering advice.. making an engine designed to handle stress from gasoline combustion, to operate as a diesel with the much higher compression ratios was doomed from the start.. but it was driven by the oil crisis and need to improve MPG, and quick. The business side over any engineering common sense on that debacle. 

In contrast, the old Land Rover's had an engine originally designed for Diesel, that they converted to use gas, and it was way over built for the lower compression and stresses and would run reliably, generally considered a big success. Lots of those still on and off the road after decades in use, quite the contrast to the old GM diesel disasters.


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## Barry Allen (Apr 18, 2018)

It took some work with an impact wrench to get the filter canister loose from the housing. This was the comparison of old filter and new after 40,000 miles:


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## spaycace (Feb 9, 2012)

The Cruze and 6.6 Duramax do list the same part number for a fuel filter (23304096) Fuel Filter(replaces pn 23456595) - GM (23304096) | GMPartsDirect.com but that number is for a Silverado/Sierra without water separator. There is a different filter element listed for the 6.6 with water separator. The picture on the gmpartsdirect website shows the same picture for the 6.6 Duramax, and the Cruze for that part number as well, but when I searched the website using a 2018 Silverado w/6.6 Duramax, the website said the plug (22937280) and the reservoir (23217900) parts listed for use on the Cruze would not fit on the Silverado. Bear in mind, that GM has been known to use different part numbers for the same part, so it's probably best to ask your chosen diesel mechanic in order to be safe, instead of assuming that because the same filter is used, the rest of the parts are the same as well.


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> It took some work with an impact wrench to get the filter canister loose from the housing. This was the comparison of old filter and new after 40,000 miles:
> 
> View attachment 286185


This is why I will always be changing mine a bit early, yep,that is typical. What was the fuel filter monitor saying at 40K?


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> This is why I will always be changing mine a bit early, yep,that is typical. What was the fuel filter monitor saying at 40K?


At 39,230 miles it was reading 9% life left. 

This was the first fuel filter change and my cousin (using his lift) wasn't impressed with the cheap/flimsy plastic mount of the filter canister. Using the wrench seemed to torque it too much so I put an impact hammer on the lowest setting and we figured the sharp impact would break that canister loose from where the gasket was probably a little sticky/tight. He held the base of the canister and with just a couple seconds the canister easily broke free.

I was driving home and couldn't get the fuel filter life monitor to reset. I went to the dealer and the service writer couldn't get it reset either, so we set an appointment with a tech to look at it. Before leaving I had a thought and I was able to reset the monitor by doing it while the engine was not running. Neither of us were aware that you can't reset the monitor while the engine is running.


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## chadtn (Feb 27, 2018)

Barry Allen said:


> Neither of us were aware that you can't reset the monitor while the engine is running.


I battled this the other day and it took some heavy internet searching before I found a post specifically stating the engine has to be off to reset the fuel filter monitor. Pretty sure the oil monitor doesn't care if the engine is running, but you'll never get the fuel monitor reset if it is. heh...

Chad


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