Hey I got a question. I just got my cat fuel filter adapter and filters in the mail today. I've been reading extensively the past few days trying to figure out if it's actually going to help my fuel system. Some people say the cat filter in the stock filter position with an adapter will restrict flow to the cp3 causing it to wear out, while others say it's less restrictive and provides cleaner fuel to the pump and injectors. Of course either way, the latter Is true. What are your thoughts on the restrictiveness of the cat 1r-0750 filters compared to stock filters.

I also have another question about the water-fuel separator. Of course the 1r0750 doesnt have one and I dont have a lift pump, so does that mean the water contaminated diesel fuel will get into my system? Once again, I've tried researching this as well. I found people saying the cat filter blocks out the water from entering the system; it just doesnt have a drain for it.
I'm sure people run the cat filter and adapter setup without a lift pump with a proper water-fuel separator and have no problems. I just want to know if its healthy for the fuel system and engine.

Forgot to mention, this is on a 2004 lb7. Not sure if that's useful.

In the aftermath of the LB7 injector failures 12+ years ago, with the stock filters available at the time, the adapter made $en$e, as it had a better micron rating (thought to be the cure for injector failures at the time) AND cheaper filter units compared to the $50+ price of the stock filters.

That all changed 'bout '07 or so, when the acDelco filter changed to the Racor made dual stage Coalescer filter (which you could buy the Racor brand for 'bout $30).
The new specs on it made the Cat adapter choice obsolete.

Also 'round that time, the ISO standards changed in testing. The particulates filtered didn't change in size, just the testing. But it seems even today, the sellers of the adapters still claim specs that were based on the old outdated standards, AND outrageous claims of the stock filters' low specs (again, pre-'07 data) in comparisons.

2019 and the acDelco has again changed with the new designation TP3018, with an absolute rating in the upper 99% @ 4 microns. You can't get much better than that, and it's where Bosch would like to see your clean fuel at.

The kitty is 98%. AND, it's designed as a secondary filter, with no water protection.
But you still get the baby puke yellow addicted naysayers who claim it does separate water, as they also cling to the old outdated ratings of 2 microns.

Present day, You're better protected with a stock filter.
That $100 for an adapter is better spent on an aux FWS filter and a small lift pump for positive pressure forward, which does away with aerated fuel from vacuum leaks in a decaying older fuel system.

And, both will aid in extending the life of the stock filter up front....to as much as 15k miles or more. (some see 20k+)

Better particulate filtration, better water protection, and better air-in-fuel protection.
A small pump is all that's needed, instead of the more popular 100gpm fire hydrants sold by the major two.

Yes quite happy with Kennedy pump. Easy install and it fails injection pump can pull fuel thru it with little effort.

There are many options, but I don't think simply replacing the OEM filter head and using just the CAT filter is the best, and probably is not a good idea. (Opinions vary, of course.)

Personally, I have:
- a Kennedy single pump (I don't run any tuning) as close to the tank as I could,
- over to a Nicktane filter head (there are cheaper options available now but I got mine 13 years ago or so),
- on that filter head, I run a Donaldson P553207 with a water glass bowl on the bottom (I originally ran the CAT 1R-0751, but the Donaldson has better specs and better water separation), and
- run a Racor PFF50216 on the OEM filter head (as others stated, it's the best!).

Two layers of good filtration; two layers of water separation. Running a big filter before the OEM filter greatly increases the likelihood of continuing down the road if you picked up a bad load of diesel. It also extends the life of the filter on OEM mount which is a lot harder to change.

Personally, I would not run the CAT filter on the stock filter head without a lift pump. The lack of water separation is what does it in for me. Plus the Racor, AC Delco, and Baldwin filters for the stock filter head are so good these days.

The small difference between the fire hydrant lift pumps and Kennedy, is they return what fuel is not needed at the engine back to the tank. Kennedy doesn’t have a return but it’s really not needed with the low psi output.

Either way having a LP it doesn’t matter if it’s a FASS, Airdog or Kennedy, as long as you have a LP preferably with filters a water separator and fuel filter along with the stock fuel filter, this is a good thing.
If your planning on adding a bunch of power the fire hydrant LP’s might be a better choice.

Me, I went with Airdog 4G100 which came with everything needed including filters, water separator and fuel filter and has a lifetime motor warranty.
With a AC Delco 3018 stock location (made by Raycor) with the WIF sensor connected and in place.
My AD LP is also a flow thru so if the LP motor fails the engine will still perform the same way as it did without a LP.

I have a toggle switch to power mine off under the dash, when I feel it’s time to turn’er off, which I’ve even towed with my LP off.
Not on purpose, I just forgot to turn’er back on after leaving a shop that did some work on it.

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Hey jake111!

I just purchased the in-tank fleece lift pump for my '12 LML and I was planning on keeping the stock fuel filter in the engine bay but was also looking to add an in-line fuel filter somewhere underneath to give me another place of filtration... If I am understanding what you said above, you mounted a nicktane adapter underneath your truck along the frame somewhere between the kennedy and the stock filter? My goal here is to feed my CP4 the cleanest fuel I can and from my research the CAT fuel filter on the OEM filter head alone isn't the way to go. Any and all information is good!

P.S. I am new to the diesel world and have loved reading and learning so thank you in advance for the help!

Yep. For my truck generation, I had to drop the driveshaft and lower the fuel tank to reach the top. Originally I just ran the Nicktane kit, but almost 2 years ago I added the KD lift pump. The kits came with connectors for the top of fuel tank. Instead of fuel lines from the kits, I bought "Gates 27316 Barricade Fuel Line Hose" which is rated for biodiesel and has very good specs otherwise (you can search to fine). So, line goes from the tank to the lift pump, then from the lift pump to the aux filter, then from the aux filter it ties back to the original line (near the cooler, FWIW, because yours is probably quite different).

Also, FWIW, the Nicktane came with a very beefy bracket and the whole thing mounted in front of the driver side rear wheel. But it exposed the filter to the wheel, so I turned the whole bracket around so the filter is protected from anything flinging from the rear tire. It mounts high enough that it's well protected from everything.

Aux FWS filter should be before the Lift Pump, not after.
You're wanting to 'pull' the fuel thru for water separation, not push it thru.