2004.5-2007 Dodge 5.9L Cummins Lift Pumps

Lift pumps on the 2004.5-2007 RAM 5.9L Cummins

Your 5.9L Cummins runs a Bosch high-pressure common-rail system built from five main pieces: the electric lift pump, the fuel filter and housing, the gear-driven CP3 with its internal gear pump, the fuel rail and six injectors. The lift pump starts the chain. It pushes fuel at roughly 10 psi through the 7-micron Fleetguard FS19856 filter and water separator. The CP3's gear pump raises it to 80-180 psi, and the pump's three plungers build anywhere from 4,251 to 23,206 psi in the rail. Everything after the lift pump depends on it keeping the CP3 fed.

What fails and why

Diesel Hub puts the expected life of the factory 24-valve lift pump at about 100,000 miles. The engine-mounted pump used through 2004.5 sits next to the filter housing, soaks up engine heat and has to pull fuel all the way from the tank. The in-tank pump that came in for 2005 has a better reputation for lasting, but it is still a wear item. The number to watch is fuel pressure. Under about 5 psi at full power means the pump is falling behind.

A weak pump does more than strand you with a no-start. A starved CP3 gets damaged quickly and can send metal into the injectors. Injector replacement on this engine runs about 8 hours of labor, and because one injector costs nearly as much labor as all six, most shops replace the set. Keeping the lift pump healthy is how you stay out of that job.

Stock replacement vs. upgrade

If your truck is stock and the pump simply quit, an OEM-style replacement puts the fuel system back the way it left the factory. If you have raised rail pressure, for example with Stage 1 or Stage 2 performance injectors, TDR's guidance is to move to an aftermarket lift pump and filtration system with about 3-micron filtration, finer than the factory 7-micron filter. Pair that with a fuel-pressure gauge so you can see the pump's health instead of guessing. When you choose a kit, the engine-mounted versus in-tank split decides what fits.

What we carry

This collection is BD Diesel fuel lift pumps:

• BD Diesel 1050231 OEM Replacement Lift Pump, listed for 2003-2004.5 Cummins trucks. This is the match for a 2004.5 truck that still has the factory engine-mounted pump.
• BD Diesel 1050226 Auxiliary Lift Pump, listed for 1998.5-2007 Cummins trucks, a range that covers every year on this page. Read the product page for how it plumbs into your truck.

For other lift pump options, see our lift pumps page.

Fitment notes

Do not order by the calendar alone. Mid-2004 (2004.5) trucks have the engine-mounted pump, and the in-tank module starts with 2005. Open the hood and look beside the fuel filter canister before you buy. If the pump is there, you need the engine-mounted style. On 2005-2007 in-tank trucks, some aftermarket pumps also need an optional pickup tube. 2007 is a split year: trucks built after January 1, 2007 got the 6.7L Cummins, so match a 2007 by engine, not model year. When in doubt, verify by VIN.

Frequently asked questions

Where is the lift pump on a 2004.5-2007 5.9L Cummins?

It depends on the year. Mid-2004 (2004.5) trucks have it mounted on the engine next to the fuel filter canister. 2005-2007 trucks have it inside the fuel tank as an in-tank module. Look before you order, because the two take different parts.

How do I know my lift pump is going bad?

Watch fuel pressure. The factory pump runs around 10 psi, and pressure under about 5 psi at full power means it is not keeping up. Left alone, a failing pump can leave you with a no-start and can starve the CP3, which damages the pump and the injectors behind it.

How long does the factory lift pump last?

Diesel Hub gives the factory 24-valve lift pump an expected life of about 100,000 miles. The engine-mounted pump has the harder job because it sits in engine heat and pulls fuel the length of the truck. The 2005 and later in-tank pump has a better reputation, but it still wears out.

Do I need an aftermarket lift pump with performance injectors?

That is the recommendation. Any time rail pressure goes up, TDR advises an aftermarket lift pump with about 3-micron filtration to protect the CP3 and injectors. Pair performance injectors with a fuel-pressure gauge so you can watch supply pressure.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.