Water in Fuel Bleed-off

[Cougar]

I have a 2008 Chevy 2500HD Duramax diesel LMM with Allison transmission.

What is the recommended access to the fuel filter to bleed off any water which has collected?

Should I access from the engine compartment or from underneath?

Should this be done on a regular basis or only when I get a "Water in Fuel" message on the DIC?

[DmaxMaverick]

The water drain valve has a nipple on it, and will fit a length of hose (about 1/4", IIRC). Best access is over the tire, and under the fender liner. Just reach in and give it a turn. I recommend a hose or suitable container, as the fuel will dissolve the frame wax coating. Clean up any fuel quickly and wash with soap/water.

You shouldn't have to drain water between filter changes. If so, you should consider another fuel source. And, use an additive with water handling ability.

[Cougar]

Best access is over the tire, and under the fender liner.

How do I remove the fender liner?

[DmaxMaverick]

While it would certainly offer a much better/easier access to the filter for draining, fender liner removal is not necessary. It makes filter changing a snap, but it is not required to access the water drain valve. You should be able to "pull back" a portion of the liner (from the outside of the wheel well, above the tire) for a visual, but once you know where it is, you can access and open the valve by hand/feel. The bottom of the filter is located rear/above the shock.

Use caution with the WIF (Water In Fuel) harness, which is the wires attached to the bottom of the filter. They are not well secured and don't have a strain relief (too much movement and the wire will break where it enters the sensor). No biggie if you are aware of it, and is fine if not strained (the harness connector is a few inches forward/inward). It needs to be disconnected before filter replacement.

If you need to remove the liner, pull all the plastic body fasteners (pull out the inner pin, then remove the outer/larger part), wire loom clamps (they just pull out, but check the other side). Once all the fasteners are removed, the liner can be wiggled out. It's a snap once you've done it a time or two.

[jbplock]

..Use caution with the WIF (Water In Fuel) harness, which is the wires attached to the bottom of the filter. They are not well secured and don't have a strain relief (too much movement and the wire will break where it enters the sensor)...

Good point DM .. A while ago I noticed the wire on my WIF was starting to fray and would soon break .. I used some epoxy stick (http://www.devcon.com/products/products.cfm?market=Maintenance%20%26%20Repair&family=Magic%20Bond%E2%84%A2%20Epoxy%20Stick) to add a strain relief - seems to be a permanent fix.

[DmaxMaverick]

Good point DM .. A while ago I noticed the wire on my WIF was starting to fray and would soon break .. I used some epoxy stick (http://www.devcon.com/products/products.cfm?market=Maintenance%20%26%20Repair&family=Magic%20Bond%E2%84%A2%20Epoxy%20Stick) to add a strain relief - seems to be a permanent fix.

Exactly what I thought, after the fact. The harness was already in the glove box before I got serious about it (the feeling passed....harness is still in the glove box). One of these days, I'll solder the harness back in, and fab a strain relief.