Fleece Performance 07.5-10 GM Powerflo In-Tank Lift Pump
FPE-34790 is the Fleece PowerFlo in-tank lift pump built for the LMM Duramax: the 2007.5-2010 new body style Chevrolet Silverado and GMC Sierra 2500HD and 3500HD. Owners usually land here for one of three reasons. The truck falls on its face when towing, the fuel level sender has failed and the tank is coming down anyway, or the truck is tuned and the factory suction-fed setup is no longer enough for the CP3. This unit replaces the factory in-tank sending unit with one that carries its own pumps.
From the factory, the LMM has no electric lift pump. The CP3 pulls fuel from the tank on its own, so every foot of fuel line and the filter head work under vacuum. Any weakness on that side, such as a loaded filter, a small air leak or an aging pickup, shows up first as rail pressure that cannot keep up at high load. The PowerFlo adds two gerotor pumps in the tank and changes the system from pull to push. Fleece lists 10-13 psi at idle for this unit and rates it for up to 800 hp, including dual CP3 builds.
The pumps sit in an active fill bucket that stays full on its own. That means no sump, no draw straw and no extra air filtration, and it avoids the quarter-tank fuel starvation that is common when a high-flow pump draws through a stock pickup. Outlet and return ports take -8 O-ring fittings (3/4-16) if you later want custom lines or remote filtration.
Put in a new filter first and watch desired versus actual rail pressure while the truck is loaded. If actual pressure sags and the filter is fresh, the supply side is the place to look. Make sure the high-pressure side is not the cause: a sticking metering valve such as the Exergy LBZ/LMM inlet metering valve or a worn CP3 can produce the same low rail pressure. If the Allison is also acting up, the Allison 1000 valve body testing guide helps keep a transmission fault separate from a fuel problem.
Fleece lists FPE-34790 for:
The interchange list covers GM 19152169, 19206540, 19303427, 19303428, 19331306, 19331307 and 25350791. It is for single-tank pickups. It will not fit S&B tanks, Titan tanks should be checked against the Fleece chart, and cab and chassis trucks must match their sender number before ordering. A 2007 classic body truck with the LLY or LBZ takes the FPE-34789 instead, and 2011-2016 LML trucks use a short bed or long bed specific PowerFlo. The 2007 model year is the one that trips people up, so give us your year and VIN if you are not certain. More Duramax-era parts are on the Allison 1000 page.
Plan on 2-3 hours with the tank lowered. Work with as little fuel in the tank as you can. Clean around the sender before opening the tank so no dirt falls in. Mark how the factory unit sits, drive the lock ring out with a punch, and fit the new tank O-ring from the kit. Clip the float arm onto the level sensor and press the cap down on the bench to check that the arm never touches the pump wires or tubes. Set the unit in already aligned, because turning it inside the tank can damage the float arm.
The supplied relay harness gets battery power through its own fused lead and a trigger from a 10A switched ignition circuit through the included fuse tap. Do not fit a bigger fuse than supplied. Make sure the quick-connect fittings are fully latched, never run the pump dry, and fill with fuel before the first key-on. A new filter goes in at the same time. If you are building power, the Exergy LMM Sportsman CP3 is the matching high-pressure step.
| Brand | Fleece Performance |
| Part number | FPE-34790 |
| Fits | Fleece Performance 07.5-10 GM Powerflo In-Tank Lift Pump |
| Type | Fuel Pump Hangers |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
It depends on the body style. A 2007.5 new body truck with the LMM takes FPE-34790. A 2007 classic body truck with the LLY or LBZ takes FPE-34789. Send us the VIN if you are unsure.
Fleece lists 10-13 psi at idle for this pump. The factory LMM system has no lift pump at all, so any positive pressure is an improvement over the stock suction feed.
Only if the sender part number matches the Fleece cross-reference. The listing is for pickup trucks, so check the number on your factory unit before ordering.
It does not fit S&B tanks. Some Titan tanks accept it; Fleece publishes a Titan fitment chart to check your tank model against.
The kit includes the pump with float arm, a relay wiring harness, and the tank O-ring. Plan on a new fuel filter, clean fuel lines and fuel line disconnect tools.
Yes. The PowerFlo includes the level sender and float. Check that the float arm clears the wires and tubes through its full travel before you install it.
