How to install a BD FlowMax 6.4L Ford lift pump kit
BD’s FlowMax Lift Pump Gives Modified 6.4L Ford Diesels the Fuel Needed for Big Power and Low EGT
Dumping a wad of money into an engine in an effort to improve its performance can be frustrating. You step up to bigger injectors, a sweet turbocharger, a great tune, and other intake and exhaust modifications, only to find high EGT and other problems hold your rig back when you put the hammer down.
High EGT under load and other fuel-related problems typically stem from the OEM lift pump not being able to supply the engine with the fuel volume it needs to produce the power being demanded. Whenever the mismatch occurs, bad things happen—usually very quickly.
“Anytime 6.4L Fords are producing more than 350 hp, the OE lift pump and fuel system’s inability to keep the fuel supply pressure at an acceptable level becomes an issue,” explains Christian Roth, vice president of BD Diesel Performance.
“You immediately see a negative performance once that pressure drops below a net zero on the inlet side of the high-pressure pump,” he adds. “The pump cavitates, creating air bubbles in the fuel system. As a result, that creates a giant restriction, which in turn causes the rail pressure to fall. That’s when you see the real serious performance side-effects happen, such as a spike in EGT when towing up a grade.
“For example, the factory 6.4L Power Stroke ECM commands 20,000 psi rail pressure. If there’s not enough fuel supply at the high-pressure pump’s inlet for that 400, 450, 500, or 600 hp, the rail pressure starts dropping—a nd it continues to drop as the fuel demand increases. Meanwhile, the ECM keeps asking for additional [fuel] supply to try and maintain that 20,000 psi. But there’s no more fuel available, because the OE lift pump is maxed out.”
“In turn, the computer says, ‘Rail pressure is now down to15,000 psi rather than 20,000 psi, so I’ll extend the injector ON time to help create more torque to meet the driver’s throttle demand.’ The direct result of the injectors being open for a longer duration is higher EGT,” adds BD’s Jeff Harris.
It’s actually a common issue for ’08-to-’10 6.4L Ford Power Stroke engines that are still running the stock HCFM (horizontal fuel conditioning module) and making between 400 and 600 hp. Adding a high-volume, low-pressure replacement HCFM and BD Diesel Performance FlowMax Lift Pump kit usually resolves the issue.
The FlowMax pump’s volume is 2.5 times greater than the stock pump’s volume at a higher pressure (Ford’s 6.4L lift pump flows 60 gph at 1gpm while BD’s FlowMax delivers 150 gph at 2.5 gpm), which is enough to keep even a 600hp 6.4L Power Stroke happy at full-throttle, or when towing a trailer up long grades.
The quiet, easy-to-install pump simply mounts to an ’08-to-’10 Super Duty’s outside framerail and plugs right into the factory wiring harness. It took Mobile Diesel Service Technician Josh Hunt approximately 30 minutes to install one on a customer’s 500hp ’08 F-250.
BD Diesel Performance’s ’08-to-’10 6.4L Ford Power Stroke FlowMax Lift Pump Kit includes everything needed to replace the stock horizontal fuel conditioning module (fuel pump module), including a wiring harness, fuel line, couplers, and connectors.
The first step in the installation is unplugging the gray fuel pump sub-harness connector that’s located just above the HFCM and releasing it from the clip that holds it in place.
Quick-disconnect release tools are used to remove the ½-inch feed and 3/8-inch return (upper) lines from the engine side of lift pump, and the back of the HFCM.
Josh removes the three 13mm nuts that hold the stock lift pump to the driver-side framerail.
The original HFCM is no longer needed with the BD Diesel Performance FlowMax lift pump, so feel free to offer it to a buddy who has a stock 6.4L Power Stroke.
BD’s supplied bypass tube connects the return (upper) lines.
Josh once again uses a ½-inch quick-disconnect tool to remove the engine fuel-feed line from the barbed fitting located just behind the driver-side engine mount. It will be replaced with a new ½-inch fuel line that’s included in the FlowMax kit.
We opted to mount the new pump using the supplied, stainless steel frame bands instead of drilling holes and mounting it directly to the framerail.
Moving the emergency brake cable bracket downward (closer to the frame) places it clear of the BD lift pump bracket. Josh relocates the bracket by removing its 13mm bolt, drilling a new 3/8-inch hole for the bracket’s locking tab, and then swinging the bracket and cable assembly downward and securing it.
The BD FlowMax lift pump assembly mounts against the frame, with the “IN” on the fuel-filter head facing the rear of the truck. Make sure the emergency brake cable doesn’t rub on the mounting bracket. Stainless steel bands secure the bracket to the framerail.
The kit comes with 8 feet of ½-inch fuel line. The supplied plastic quick-connect fitting is placed into one end of the hose and the steel quick-connect-to-hose adapter is fitted in the other. Hose clamps are used to secure each.
Josh snaps the quick-connect fitting onto the steel line at the engine and connects the other end to the fitting on the line from the tank (where the HFCM was removed earlier).
A hose cutter is needed for splitting the fuel feed line so it can be fitted on the inlet and outlet of the new pump.
The new supply line is routed from the fuel tank over the framerail, then attached to the “IN” side of the fuel filter adapter. A supplied gear clamp secures the hose to the fitting.
Fuel line coming from the engine also drapes over the framerail and is attached to the “OUT” port of the FlowMax lift pump. (BD offers an optional water separator filter/head if one is needed.)
Josh plugs BD’s adapter harness into the factory lift pump’s sub-harness, then connects the other end of the adapter to the plug for the FlowMax.
A water-in-fuel sensor fits in the bottom of supplied Donaldson fuel filter. Josh fills the filter with clean diesel fuel to quick-prime the pump, spins the filter onto its adapter, and then plugs the remaining connector of the adapter harness into the WIF sensor.
After rechecking all fittings, brackets, straps, and connections, the upgraded truck is ready to rock. Enjoy the power!