Need Help, Fuel draining back

[alexx1060]

looks like it might be the pickup lines in the tank, any videos anywhere on how to replace them? :D

dad took the main line from driver's side tank and stuck it in a container of diesel and found no bubbles when cycling the key and letting the low-pressure pump run and prime the engine. truck runs good like this and fuel doesn't drain at all from davco filter.

[Nilao]

I do believe the stand pipes have to be cut out of the tank and new ones welded back in.

[Dcolumbia]

Sounds like he needs to open the bleeder on the fuel rail and purge the air because the lift pump isn't working properly. Did you change filters doing a PM then it wouldn't start?

[amermextrucker]

last 2 oil changes on my truck Davco 382 has no fuel in it. 1st fuel filter went 20k miles and no visible fuel . On this recent service im at 1500 miles and no visible fuel yet. In the past fuel starts building after 3-4 k miles after service. Im keeping an eye on it. I watched video rawze posted on how to change. Truck fires right up , but i do notice a tad bit less power , maybe its my mind messing with me.

Im going to go to 5k miles and change filter out. If this continues ( no fuel in filter ) what should i be looking for ? my concern is filter is not doing its job and might damage something ? thoughts ? TIA.

[JimT]

Which filter did you use?

I believe there are multiple (4) filters that will fit, but another forum member said that FS 19727 is the proper one for the ISX. It's 10 micron and I remember reading something from Cummins about using a 10 micron for the davco.

Personally I've had the exact same problem, last year. Had to keep adding fuel through the top cap to make sure it didn't suck air on a steep grade.

Another thing to check is the O-rings. Make sure the cover is on properly and that the o-ring on the top cap is sitting straight and not broken or missing.

I went so far as to replace the entire unit on my truck before I installed the FS19727 filter and didn't have any further issues.

There could be other issues too, such as a bad check valve in the unit, restrictions in the fuel lines from the tank, maybe one or more clogged tank vents, plastic davco cover warped and leaking air due to over torquing, could even be the lift pump. Although I'd start by checking the filter first. Seen a few other threads on here with the same issue recently (last few months)

[amermextrucker]

(07-11-2021 )JimT Wrote:  Which filter did you use?

I believe there are multiple (4) filters that will fit, but another forum member said that FS 19727 is the proper one for the ISX. It's 10 micron and I remember reading something from Cummins about using a 10 micron for the davco.

Personally I've had the exact same problem, last year. Had to keep adding fuel through the top cap to make sure it didn't suck air on a steep grade.

Another thing to check is the O-rings. Make sure the cover is on properly and that the o-ring on the top cap is sitting straight and not broken or missing.

I went so far as to replace the entire unit on my truck before I installed the FS19727 filter and didn't have any further issues.

There could be other issues too, such as a bad check valve in the unit, restrictions in the fuel lines from the tank, maye one or more clogged tank vents, plastic davco cover warped and leaking air due to over torquing, could even be the lift pump. Although I'd start by checking the filter first. Seen a few other threads on here with the same issue recently (last few months)

Im unsure about the P/N but i do know its 10 micron filter. I saw the video Rawze posted (davco filter installation ) and that lead me to other videos on how to install and etc..
whats throwing me off is ive owned truck for 14 mos now and like clockwork after 3-4 k miles i would start seeing fuel build. Thx for the tip im going to keep an eye on it and if nothing changes replace it.

[JimT]

(07-11-2021 )amermextrucker Wrote:  Im unsure about the P/N but i do know its 10 micron filter. I saw the video Rawze posted (davco filter installation ) and that lead me to other videos on how to install and etc..
whats throwing me off is i've owned truck for 14 mos now and like clockwork after 3-4 k miles i would start seeing fuel build. Thx for the tip im going to keep an eye on it and if nothing changes replace it.

With the proper filter I still get a low fuel level in the davco for some time until it starts building up a restriction, however it no longer drops below the bottom of the clear housing. I've been doing a maintenance dose of BioborJF in the first fill-up after a Davco change for the past 8 months and this not only helps keep the microbes at bay but it seems to jump start the filter restriction slightly. My last filter lasted over 35,000 miles before it finally climbed up to the change line and the paper wasn't even black.

[Waterloo]

How old is the Davco clear filter housing? They are like $50, I was having issues after a service that sound like you are going through, and I replaced the clear plastic dome housing, problem solved. The plastic had fine cracks in it. Might want to try replacing.