LB7: Deleting stock filter head when running airdog?

[Hot COCOAL]

The filter head does indeed have a small 12v heater in it that supposedly is active at temps below 58 or 48* F.

To me it seems kinda redundant, and would only work to warm gelled fuel "in" the filter/filter head and not eliminate a gelled fuel issue long enough to keep the truck running. Some have said its there to help with water build up in the filter head? Something about the temp change and condensation? I don't know for sure the intended purpose of the little heater, but it's there, mine had it, I removed my filter head and plan to use an additive during the winter if the temperature drops low enough.

The way I see it, with something like the ADII, the fuel gets the condensation removed, which helps to keep it in liquid form, and also gets pressurized by the pump which should help to get the fuel through the lines as well, then the fuel gets warmed by the running engine, through the lines as they pass through the engine bay and over the block, return fuel even goes through a fuel cooler, so I feel like as long as the truck starts, I should be good

 

[rg3whitelbz]

Mine pissed me off when the seal kit didn't fix it so I took my extra hose from installing my airdog last year and two hose clamps and looped it. Looks a little cleaner too.

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[btfarm]

The little heater element in the filter head is probably to keep the check ball from waxing up and sticking at startup. Once the flow is going it isn't needed. It's probably tied to the WTS GP circuit. It certainly wouldn't be needed if a lift pump is used.

 

[baggedLB7]

I was thinking of ditching my factory filter head until I relized that if I was out on a road trip or somthing and my airdog stops working I would half to bypass the airdog to get enough fuel to run the truck down the road and by doing that if there is no factory filter you would have no filtration at all.
So I decided to keep it just in case and could be a reason for some to keep it also.

 

[OregonDMAX]

I was thinking of ditching my factory filter head until I relized that if I was out on a road trip or somthing and my airdog stops working I would half to bypass the airdog to get enough fuel to run the truck down the road and by doing that if there is no factory filter you would have no filtration at all.
So I decided to keep it just in case and could be a reason for some to keep it also.

Why would you have to bypass the airdog? Pretty sure that are all flow through.
Fwiw I blew a fuse and still drove 40 miles before I noticed the airdog wasn't even working.

 

[baggedLB7]

Mine wont even sit in the drive way for very long running without the fuse in it before it shuts off and I know of others that have the same issue with there airdog. I do know they are supposed to be flow through but mine does not.

 

[OregonDMAX]

Oh dang that sucks I guess its better to leave your filter head on then

 

[Hot COCOAL]

Why would you have to bypass the airdog? Pretty sure that are all flow through.
Fwiw I blew a fuse and still drove 40 miles before I noticed the airdog wasn't even working.

Mine wont even sit in the drive way for very long running without the fuse in it before it shuts off and I know of others that have the same issue with there airdog. I do know they are supposed to be flow through but mine does not.

My guess is one of you has a sump in the fuel tank and one of you doesn't, or a weak cp3 that won't pull through the AD

I have a sump and the pump flows fuel thru it when it's off, or the fuse is pulled, I ran it with the fuse pulled after I re-flashed the ECU, I unplugged it cuz I didn't want it running for the 8min it takes to flash while the ignition was in the key on engine off position, then forgot to plug it back in (I was excited lol) and drove the truck 20miles or so. Also, with the sump in place, when I do a filter change on the ADII, fuel pours out the spout that feeds the filter, it didn't before when I was using the factory fuel pick up.

 

[OregonDMAX]

No sump here and fuel pours out on mine too during a filter change if I don't pinch the hose. Could be a weak cp3 or a weak AD pump. Good thing for the lifetime warranty.

 

[JoshH]

The little heater element in the filter head is probably to keep the check ball from waxing up and sticking at startup. Once the flow is going it isn't needed. It's probably tied to the WTS GP circuit. It certainly wouldn't be needed if a lift pump is used.

The little check ball only closes when the filter is removed. If you look down in a fuel filter, you'll see a little finger that pushes the ball when it is screwed on.

 

[bmos37]

I deleted my stock filter on my LLY when I put the airdog 150 in never ran into any problems and saved a good amount of money over the 4 yrs.

 

[AKRiverRunner]

Dayco #71359 is a bypass hose

I found this on another forum about deleting stock filter. I have this and all the parts to install my lift pump and CAT filter and delete the stock filter. I need to change injector #5 so I'm going to pull it then.

 

[plowboy_lbz]

Dayco #71359 is a bypass hose

I found this on another forum about deleting stock filter. I have this and all the parts to install my lift pump and CAT filter and delete the stock filter. I need to change injector #5 so I'm going to pull it then.

I see this is a radiator hose. Will this work with diesel fuel? I know sometimes different rubbers don't work with certain liquids because they will actually eat up the rubber. The last thing I want is pieces of rubber flowing into my $1200 cp3!

Also no problems with flow through on the AD. If your AD doesn't flow through then you have a problem.

 

[btfarm]

The little check ball only closes when the filter is removed. If you look down in a fuel filter, you'll see a little finger that pushes the ball when it is screwed on.

No argument Josh but based on what I saw when I worked on it and the following from a good source I'm not sure that's correct since no flow happened in the following until 5" Hg. Maybe you're right but I've never seen anything in a filter close enough to touch the ball. You can bet I'll be looking at one tonight though...

"...Another mod you can do is to open up your filter head and take right at 2 rings of the main check ball spring off to lessen the amount of vacuum needed to pull fuel through the filter head. I checked a new filter head with a vacuum pump, and found it took almost 20 inches of vacuum to fully open the check ball(it took 5 inches of vacuum before it even flowed). I know I gained almost 3000 PSI of rail pressure with my failing CP3 by modifying the filter head check ball spring."

 

[JoshH]

No argument Josh but based on what I saw when I worked on it and the following from a good source I'm not sure that's correct since no flow happened in the following until 5" Hg. Maybe you're right but I've never seen anything in a filter close enough to touch the ball. You can bet I'll be looking at one tonight though...

"...Another mod you can do is to open up your filter head and take right at 2 rings of the main check ball spring off to lessen the amount of vacuum needed to pull fuel through the filter head. I checked a new filter head with a vacuum pump, and found it took almost 20 inches of vacuum to fully open the check ball(it took 5 inches of vacuum before it even flowed). I know I gained almost 3000 PSI of rail pressure with my failing CP3 by modifying the filter head check ball spring."

I'll save you the trouble. This is an AC Delco fuel filter. I'm not sure other brands have them, but here's a good picture of what I'm talking about. It's just short of about 3/8" tall. It would have no trouble pushing that ball open enough for the truck to run. The little check ball might be a little bit of a restriction on a truck that is tuned, but I doubt you would see any benefit from removing or modifying it on a stock truck. My vac/pressure gauge that hooks up to the factory test port shows 0 at idle with a new fuel filter.

 

[Chevy1925]

I see this is a radiator hose. Will this work with diesel fuel? I know sometimes different rubbers don't work with certain liquids because they will actually eat up the rubber. The last thing I want is pieces of rubber flowing into my $1200 cp3!

Also no problems with flow through on the AD. If your AD doesn't flow through then you have a problem.

ive been running 5/8" heater hose from my pick up tube to my lift pump for 3.5 years now. its in better shape than the blue AirDog fuel line lol

 

[btfarm]

Got it and thanks for the clarification. I'm running Parker/Racors that are identical so I see what you're talking about. I did eliminate the P0087 after doing the coil trim but that could easily have been the new filter as well. Can't hurt anyhow.

 

[andy-stevenson]

I deleted my factory filter after finding I had a leak. I also switched the airdog filters to the cat. I also bypassed the hard fuel line that supplys the engine, just ran the blue airdog line right to the engine.

 

[Ne-max]

I just ran my fuel line from airdog right to the cp3.

 

[btfarm]

Got it and thanks for the clarification. I'm running Parker/Racors that are identical so I see what you're talking about. I did eliminate the P0087 after doing the coil trim but that could easily have been the new filter as well. Can't hurt anyhow.

And confirmed



So that again begs the question. ..WTH is the little heater supposed to do?

No. .. not THAT little heater.