Fuel filter

roxyfever

New member
Feb 11, 2016
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terrell tx
You dont have to delete doesnt hurt to keep it in there. Just extend its change interverals. If it was me id get the fass delete bowl for factory spot then just it case i would need to i could still prime the system
 

DmaxDrew

New member
Dec 24, 2014
110
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Texas
Thanks for the info. One more question. If my Fass system stops will it still filter the fuel? Will the cp3 suck it through the Fass system if its not working? A little confused.
 

kiwilml

Member
Nov 4, 2015
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16
Uh my cp3 works just fine pulling through my fass 150. I had a fuse blow the other day and I ran for a couple days just like normal so you shouldn't get stranded because your lift pump quit.

And I would think it'd still filter like normal too..
 

Awenta

Active member
Sep 28, 2014
4,090
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CT
They are flow through by design but sometimes they don't flow so well

Sent from my SM-N910V using Tapatalk
 

kiwilml

Member
Nov 4, 2015
454
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16
True, I watched my rail pressure and made sure it stayed close to desired and was easy on it and never noticed any difference.. I'm sure it wouldn't have held pressure if I woulda stomped it on my big tune..
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,610
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Mid Michigan
They are flow through by design but sometimes they don't flow so well

Sent from my SM-N910V using Tapatalk

They are only "flow-thru" under part-throttle regular driving conditions. Not great when getting on the highway, though.
But definitely not at WOT.
 

drperry

New member
Jan 4, 2015
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1
Also helps to unhook the power, if the fuse didn't blow. If it's the electrical side of the motor that crapped out, having power to it can lock it in place.

You'll still be pulling fuel through the FASS filter, but might as well as keep the stock filter and double the mileage between changes, or whenever the truck tells you to.

Extra filtration is a good thing. Especially for me, since I have the CP4, lol.
 
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nick31

New member
Apr 14, 2016
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Have my stock filter and housing/lines all completely removed. If you have the factory filter still in place it is supposed to flow through, but when mine went down last winter it would not flow through and I was stuck on the road, that was when I still had the factory setup and a cp4. Now have a cp3 and my fass feeds directly to my cp3, so if my pump dies again the truck will just die, no vaccum in the system anymore.
 

c20elephant

C20ELEPHANT
Apr 25, 2013
2,065
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Phoenix, Arizona
Also helps to unhook the power, if the fuse didn't blow. If it's the electrical side of the motor that crapped out, having power to it can lock it in place.

You'll still be pulling fuel through the FASS filter, but might as well as keep the stock filter and double the mileage between changes, or whenever the truck tells you to.

Extra filtration is a good thing. Especially for me, since I have the CP4, lol.

When a gear rotor positive displacement pump like the FASS or Airdog quits disconnecting the power supply will not make a bit of difference for the fuel to flow through the unit.
 
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NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,195
360
83
At Da Beach
I left my stock filter. I have 45k on my LML already and still haven't changed the fuel filter. I did the same thing on my LMM and cut the filter open once, it looked brand new inside, air dog caught all the trash and water. Just leave it on the truck...
 

jlawles2

Well-known member
Jan 28, 2010
1,057
39
48
Danbury, TX
I left the factory head installed. Worst case if something happens, you can always bypass the FASS with a hose connector and be back on the road.
 

outtatimexx

New member
Aug 21, 2017
21
0
1
Perry, Ga.
Hi; I know this is an old thread, but I have a question. I have an "02 LB7 stock. If I go to a Fass system, can I just simply leave the 3 micron Donaldson filter on the stock filter housing? Is this too much filtration? Or should I buy the filter delete setup and leave the primer in place? Thanks!
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
Hi; I know this is an old thread, but I have a question. I have an "02 LB7 stock. If I go to a Fass system, can I just simply leave the 3 micron Donaldson filter on the stock filter housing? Is this too much filtration? Or should I buy the filter delete setup and leave the primer in place? Thanks!

You can leave it. Just change the filter when you install the fass and forget about it..