Click for Coverage
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler
Subscribe to the Free

How-to Replace Bad In-Tank Fuel Pump on Older EFI Ford Trucks

Posted in How To: Tech Qa on December 11, 2017
Share this

Ford EFI pickups and Broncos from the late ’80s through the mid ’90s had their fuel pumps located in the tanks. When a pump dies or the filter gets plugged from rust and years of use — and they’re notorious for doing so and at the most inopportune time — you aren’t going anywhere. The good news is removing and replacing the pump is easy once you can get at the tank.

The easiest route on pickups (F-150/F-350) is to drop the bolts holding the bed to the frame, disconnecting the battery, disconnecting fuel filler hose, and tilting the bed upward so you can easily reach the top of the tank(s). Fullsize Broncos require dropping the tank. That entails having as little amount of fuel in there to minimize weight, and then removing the filler hose, tank straps, and protective skidplate, which is all that holds the tank in place.

If the fuel gauge was reading correctly before the pump failed, there’s no need to buy anything more than a fuel pump module, which typically comes with the strainer sock, replacement gaskets for the fuel pump assembly hanger, and new clips for the fuel lines leading into the tank. The plastic module (housing) that contains the pump, can be found for less than half the price of the entire fuel pump sender assembly, with prices on Amazon in the $40-$80 range depending on the truck and brand of pump.

You just unbolt the old module, snip the two wires, and reinstall the new unit. That’s what we did in replacing a failing fuel pump in our project Bronco, Eddie. The pump was getting louder day by day, and we noticed a little drop off in power under heavy throttle. (We found out the filter was nearly clogged, which was one reason for the loud fuel pump whine.)

If you can find just the pump for your truck, it’s easy to remove the top from the plastic housing (if you’re careful and patient) and replace the old pump with a new one, saving a few more dollars. You still need to replace the fuel tank gasket and the sock strainer that goes over the bottom of the fuel-pump housing.

As our photos show, the job can be done by anyone who’s even the least bit mechanically inclined and a few basic handtools. We made the tank removal easier on our lifted Bronco by using a cart with hydraulic lift that we picked up at Harbor Freight Tools. Total cost for our R&R was less than $50—and about three hours, most of which was getting the tank out and reinstalled. (The filler hose can be a real pain to get back on!). Now Eddie’s fuel pump purrs like a soft-spoken kitten and acceleration is back to normal.

A hydraulic-lift cart made the removal of the fuel tank under our lifted ’91 Bronco rather easy. The most difficult part was getting the filler neck hose loose from the tank. The 33-gallon tank was nearly empty, which also helps.
We used a punch to gently tap the lock ring counterclockwise until it was free from the tabs the ears slide under. This allows the removal of the fuel tank sender/pump assembly.
Be careful when removing the pump assembly to not bend the float wire. Otherwise it’ll have to be recalibrated.
Our pump failing may have had something to do with the nearly clogged sock screen filter (right). Always replace this filter when changing fuel pumps. This is also a good time to look inside the fuel tank. You never know what you may find. Clean it out before reinstalling the new pump and filter.
The pump module is removed by taking out the two screws that hold it to the sender assembly and then carefully sliding the tubes out of the housing.
Here’s the pump inside our Bronco’s fuel pump housing. The top of the housing is held on by a single Phillips head screw and several push-locks around the perimeter, which are easily pried open gently using a very small screwdriver.
We slid the new fuel pump module onto the sending unit tubes and crimped the new wires from it (red and black) to the wires leading down from the plug-in on the hanger. Then, we used a little 12V battery charger to test the connection. (You don’t want to get the pump in and find out the wires weren’t connected!)
The last step is to place the fuel pump/sender assembly back in the tank, install the new sealing gasket, and reinstall the locking ring. We also cleaned the electrical connector. Then, it was just a matter of reinstalling the fuel tank, hooking up the fuel lines and power connection, and getting the filler hose back in place. Easy repair. Just time consuming.

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results