Installing Universal Auxiliary Fuel Filter

[lmholmes11]

Hey everyone, I recently ordered an Universal auxiliary fuel filter from Lubrication Specialist. I read the instructions that came with it, and also the article on this web site, both are instructions for installing the aux. filter AFTER the OEM filter. Can anyone share some instructions for installing the aux. BEFORE the OEM filter? Thanks!

[richp]

Hi,

I did this myself a while back, and used the instructions Jim Begley provided in the Member's Area of the Diesel Page. I don't know if they are available elsewhere.

It basically involved following the instructions that came with the kit up to the point of installing the lines. Then, you detach the fuel line between the intake on the OEM fuel filter and what looks like a silver box just forward of the filter. Replace that one line with the input and output lines for the auxiliary filter, bleed the system by pumping out from the OEM filter housing, and you're done.

FWIW.

Rich Phillips
Member #27

[More Power]

The articles referenced in both posts above are one and the same, which show how to install the auxiliary filter inline after the factory fuel filter.

It can be found in our Product Reviews page here (http://www.thedieselpage.com/reviews.htm). :)

It shouldn't be all that difficult to plumb it in before the OEM fuel filter, but the reason why it was plumbed after was to allow the OEM fuel filter to be used as the primary (first pass) fuel filter and water separator, and a finer (true 2-micron) media filter to be used as the secondary.

Jim

[lmholmes11]

Ok thanks guys, while installing the filter and disconnecting the fuel lines, do I have to worry about them being pressurized? And also, is there a need to worry about air getting in the fuel system, (even after bleeding)? Thanks!


lmholmes11

[DmaxMaverick]

The fuel system is suction from the tank to the HP pump (after the filters, and the last stop before the fuel rails), so no pressure unless you've added a lift pump.

There's always a concern with air, but only if you have a leak. The filter should bleed easily by pumping the primer pump and bleeding out the air. Once you bleed it and it stays running, only a leak will cause a problem. A plugged filter can cause outgassing of the fuel (extreme vacuum on the fuel), but a filter change should take care of that. Usually not a problem unless you have a trap somewhere in the system (like early Mega Filter systems).

[richp]

Hi Jim,

You are The Expert on this stuff, but I'm puzzled.

The instructions that came with my kit were not the same as those you provided on the web site. In fact, the web article says,

"The instructions included with the kit show an installation on a 2004.5 or newer LLY Duramax. The fuel line routing is different from the earlier LB7 Duramax shown here. Some interpretation may be required if yours differs from either these photos or those shown in the included installation instructions."

The kit still was easy to install, even if I do have problems with nomenclature (smile).

Have a good one. and thanks for all the good work you do in keeping us up to date on the care and feeding of our trucks.

Rich Phillips
Member #27

[richp]

Hi Jim,

If you have a minute, would you clarify this one for me? I have mine installed as per the web site info, but still am not sure what these posts are actually saying.

So at the risk of exposing my ineptness, in comparing these posts, could you clarify the status of the two different instruction sheets, and the pre-post-OEM installations they describe.

Thanks.

Rich Phillips
Member #27