External Fuel Pump?

[green 788]

My fuel pump has gone on my K3500 truck.

 

I was looking at the options for replacing the pump, and I see that Autozone is listing an external pump that they show as compatible with this truck.

 

I have never heard of an external fuel pump for the newer style fuel injection systems.

 

Am I misunderstanding something? It would be nice to have an external pump so that if it did go bad you could replace it without having to drop the fuel tank to get to it.

 

My truck has a 34 gallon tank on it.

 

Any recommendations or ideas appreciated. I will be ordering a pump of some type by tomorrow, I believe...

 

Thanks,

 

Dan

[Draenor]

Usually these pumps are used on tanks with a feed line on the botton of the tank. Other wise you will need to fab up a line from in the tank to a filter, then to the pump. You may need to install another FPR inline. I dont know if the stock one would work.

[green 788]

10-4...

 

I did find out that what you said is true... they're pumps for transferring fuel from one tank to another, not for pressurizing the fuel injection system.

 

But I have replaced the pump already, today, and the truck is back running.

 

A friend and I were able to drop the tank, and drive to Advance Auto (5 minutes away) and pick up a Bosch pump and a new strainer... and get back and install it and put the tank back on in under 2 hours.

 

We work fast, but that's the honest truth. Things went quite well, as I believe that God blessed our efforts today.

 

I hope everyone's pump replacement will go as well as mine did.

 

I think we went through about a gallon and half of iced tea today.

 

Dan

[green 788]

For the archives... here is a rundown on what we did:

 

We raised the back end of the truck up about 6 inches. Depending on your truck's height, you might be able to skip this step.

 

We siphoned as much fuel from the tank as possible. I think I left 3 or 4 gallons in there.

 

We removed the screws that hold the filler neck in place, accessed from inside the tank fill door.

 

We removed the bolts securing the looms which hold the fuel lines and brake lines in place along the frame rail. There were 4 on my truck, but it's long...

 

We placed a large block under the tank, so that it would not drop too far and damage the lines. I used a block of fire wood, but you could use milk crates and slabs of wood, or whatever...

 

We then removed the two tank strap bolts. Oil these from above if at all possible, for ease of removal. They're pretty long, too.

 

We then dropped the tank down onto the block, which allowed access to unhook the lines on top of the tank.

 

We removed the bolts for two ground straps, one to the filler neck area, and another to the frame rail. These wires were part of the wiring harness for the fuel tank. Unplug the wiring harness, of course...

 

We removed the two fuel lines (pressure and return) on the tank. On my 1996 model truck, these were not the compression fittings, but rather bolt coupled fittings, which required a 3/4 inch wrench and a 5/8 inch wrench. I was sure to mark which line was which, using colored zip ties.

 

We disconnected other vent lines, etc., which was pretty easy, and lowered the tank to the ground, bringing the filler neck and hose across the frame rail.

 

Then we used a hammer and blunt screwdriver to tap the locking tabs for the fuel pump retainer ring out of lock position, then we tapped the fuel pump retainer ring in a counter-clockwise direction (yours might go differently, so be sure to watch what you're doing)... then the pump was lifted out.

 

The new pump installs per directions which you should find in the box. I researched the reliability factor of various pumps on the market and a near consensus said that the Bosch turbine pump--which eliminates the pulsator which other pumps use--was the most reliable. The Bosch pump does not make that whining noise we all have come to love, but I am given to understand that it doesn't labor as much as other pumps to accomplish the same pressures. Take that for what it's worth. I'm sure there are other good pumps out there. The OEM Delphi in my truck lasted over 200K miles (it did not appear this tank had ever been dropped, or the pump removed... I got the truck used). Another note for those who may use the Bosch turbine pump (about 100 dollars at Advance Auto--and it has a lifetime warranty also, which is bold on Bosch's part, showing ultimate confidence in their product)... but what I was going to say is that you will use a small rubber connecting hose, which is included with the Bosch pump number 69225, to replace the pulsator unit. That pulsator just pulls right off the fuel lines.

 

I used some heavy grease to pack into the crevice when we installed the new pump. Someone else mentioned that toilet seat wax is good for keeping dirt and moisture from creeping in around the pump port in the tank. I wish I'd known to use that before I did the job, because it sounded like a good idea.

 

Anyway, installation of the tank is of course in reverse order. If all goes well, your truck will run once again...

 

Dan

[superjim]

Dan,

 

Thanks for the write up.

I am sure that it will help someone in the future.

[bossier62guy]

Pulling the bed seems to be the preferred method by most here but glad you got it back up and running. Hey Jim, are you an ex SR pilot or just like the picture?