The following Tech Write up was completed on a 96 bronco and maybe off interest to those of you that have done upgrades to your engine such as larger injectors, and for those of you that just want a better quality pump.
My factory pump has been screaming like a cat caught in a blender for almost 2 years now. Not wanting to replace it with an over prices original I bought a WALBRO 255LPH fuel pump, part number GSS340 and the 400-812 install kit. This kit is made for a 5.0 mustang and is good for up to 500HP a little over kill for a stock engine which mine isn't.
The original pump flows at 125LPH, so this is a significant upgrade if I can make it work. I know the factory pump is enclosed in a plastic case, at best this will swap right in and at worst I’ll have to fabricate something to make it work.
With the fuel needle on empty lets begin.
The Kit, I also purchased a pump retainer ring – they are usually rusted past reuse.
If you can get your bronco at a comfortable height to work on
Support the tank so you can safely remove the bolts
Remove the 8 bolts holding the skip plate in place, this hold your tang as well.
Disconnect the connector to the fuel pump
Next disconnect the black vent line, the blue fuel line and the gray return line. You need to use a special fuel line disconnect tool for the blue and gray line.
Loosen the clamp to the filler
Lower the fuel tank and set it down were you can work on it. Even with the needle on empty there was still about 20 liters of fuel in the tank. This is a good time to flush your fuel tank or replace it with a new one. Even though mine looks rough its still sound so I'll just flush it.
There is a tool for this but you can make do with a blunt brass chisel. (use a brass punch and not a steel one as shown to avoid sparks) The ring removes counter clockwise.
With the ring removed you can now pull out the pump
To get at the pump you need to remove these 2 bolts and 1 on top
And here is the old pump removed from its plastic hiding place.
The old on the left compared to the new high flow on the right, notice the differences – it isn’t going to be an easy replacement.
Now faced with the fact the new pump isn’t going to be a direct replacement I need to fabricate a bracket. Here I’m deciding on a length for the bracket and that’s going to be 5 inches x 1 ½”.
Cut out of I/8” flat steel
Sorry I changed the design after realizing the pump outlet wouldn’t align with the sending unit.
I form the bracket around a steel pipe similar in circumference of the fuel pump to hold the pump securely.
Bolt it on and clamp the pump in place
Filter now in place and the wires are connected, it is ready for the tank.
Installed in the tank with the new ring and seal.
Now install the tank and test.
Happy to say the pump can no longer be heard and I’ve noticed I bit more pull during wide-open acceleration up an incline in the road to my house. I’m now ready for larger injectors!
Hope this helps.