This is the complete kit including the plunger seals. Contrary to popular belief the OE filter housing does not crack. It is typically a failed oring that is letting air in. Rebuild your housing and problem solved.

"My best suggestion is to add a lift pump. Your fuel system needs it! See my Tech Tip Duramax Injector Failures for more info." -JK

Gauge use notes:

The Duramax engine has a factory installed test port alongside the alternator. Simply remove the cap and snap my gauge onto this port and start engine. It is important to establish a baseline with clean filter(s) a full tank of fuel and on level ground. This eliminates variables in effort required to move fuel. Restriction can be checked at idle speeds and at 2-3,000 RPM. Typically we will see approximately 2-4"hg at idle with very little variance as RPM increases. As a filter loads up, you will see restriction increase. When you hit about 5-6" hg (about 2" above baseline) I consider the filter well used and due for replacement. The early Dmax single layer media filters would run a long time without much of an increase in restriction. The latest multi layer media units seem to be doing a much better job of collecting dirt, but start at a higher restriction that rises quickly as they load up. Having this gauge on hand allows you to quickly and easily verify the condition and can be very beneficial when diagnosing fuel system related drivability issues. Typical OE filter life is < 15,000 miles. We have seen these filters load as early as 2500 miles or less depending on fuel quality.

Note:

This is a flow checked device much like an air hose. It will not return to zero unless the center valve core is depressed. Additionally, the gauge housing is liquid filled so temperature/pressure changes can affect the zero point. There is a plug on the back of the gauge head that can be vented to allow equalization between the gauge and atmosphere, but be careful not to damage the plug or let the glycerin run out.

Same basic kit as the above unit with more pressure capability (15 psi) for stronger lift pump setups. Use this gauge if your lift psi exceeds approx 8psi. With the increased capacity some fine resolution is traded off.

Replace the flimsy OE plastic bleed screw with this hearty metal unit. Made from anodized aluminum to make it easy to locate and highly durable.

"Finger tight is all that these need to be. Try for yourself and you will see that it needs to be loosened significantly before it begins to allow any air or fuel to discharge."- JK

"This is the original, not the imitator." -JK

Handy wrench built specifically to remove and install the water in fuel sensor on the Dmax LB7, LLY, LBZ, and LMM fuel filters. Also has handy slotted driver at the end of the handle for opening and closing the bleeder without damaging the screw.

Replaces the OE WIF sensor with a simple, pretty much indestructible plug made of anodized aluminum. Accepts KD WIF wrench plus has a 3/4"-19mm hex to unscrew. Drilled and tapped with 1/8" NPT to accept a drain valve.

"The OE filter basically never collects any appreciable water so the sensor is pretty much useless. Over time the sensor can leak so why not just chuck it? Removal will not set check engine or water in fuel warning light."- JK

Replaces the OE WIF sensor with a simple, pretty much indestructible plug made of anodized aluminum. Accepts KD WIF wrench plus has a 3/4"-19mm hex to unscrew. Drilled and tapped with 1/8" NPT to accept a drain valve. Drain valve included.

"The OE filter basically never collects any appreciable water so the sensor is pretty much useless. Over time the sensor can leak so why not just chuck it? Removal will not set check engine or water in fuel warning light."- JK

Replacement for that chewed up leaky WIF sensor. Consider our WIF wrench so the new one does not get chewed up!