I was finally able to replace the front tank fuel pump and sending unit. After removing the tank and taking out the original fuel pump and sending unit it was easy to see what caused the failure (other than over 20 years of use, of course). The strainer at the end of the pickup was no longer attached and the strainer had dessintegrated into small pieces. Most of it was still intack but I'm sure the pump sucked up some of the screen and other crap causing the failure. I wonder if the strainer dissintegrating has anything to do with the changes in fuel since the 80's and 90s.

Anyway, after installing (also installed a new fuel filter) I notice a whine when I select the forward tank. I also had the fuel line on the output of the fuel filter come off (or blow off not sure which yet) during my test drive. I simply reattached the fuel line and double checked the duckbill clip. So far no leaks. But the whine is still there and only when the forward pump is selected.

The new fuel pump is a Carter P74518S I bought from Rockauto.com which allowed me to select the correct year, location and size. I'm wondering if anyone else has had a similar experience?

I certainly don't want fuel line blowing off again with someone else behind the wheel.

Thanks,
Roy

 

No takers... c'mon man? Okay maybe a little more info would help.

After driving around a little last night here's what I've noticed. The whine is definitely from the fuel filter and only when the front tank is selected. When I switch to the rear tank it goes away immediately. Switch back to the front and after a couple of seconds the whine starts back up. It's not as loud as a screeching fan belt or bad disc brake pads but I don't want the new pump to fail prematurely either. The HP Fuel Pump is a little noisier when the front is selected but not by a significant margin.

Appears that I may also have a fuel reservoir issue. From the little I've been able to drive since replacing the front pump the front tank seems to be getting fuller and the rear tank is emptying rather quickly. I'm going to swap out the reservoir with a spare I picked up to see if that fixes the problem and check the diaphram and o-rings on the old one.

Thanks,

 

Ill throw something out there since no one else has replied. Does it sound like maybe air is being sucked in? Is the fuel filter hooked up right? Check to make sure that is hooked up correctly. All I got man

 

No whine when the rear tank is selected. No leaks, runs fine. Recheck the Carter fuel pump and from everything I can tell its the right one. I replaced the fuel filter with a Purolator. I might switch back to the one I replaced just to see if the problem still exists.

Thanks for taking the time to give it some thought though.

R

 

Maybe check the pressure each pump is putting out, that might shed some light....

 

Good idea Martin. Although that would require real troubleshooting vice postulating, theorizing and guess work which I normally practice.

Can you actually test the low pressure pumps since the only schrader valve I'm aware of is one the fuel rail? I think that all I can check is after the fuel filter and high pressure fuel pump. I would expect there to be a slight difference between the front and rear (due to the new pump) and I guess there is a possibility its above spec. But isn't that what the fuel pressure regulator is for?

Well you've got me thinking... time to break out the test set. Thanks.

R

 

After driving around a bit the front tank was definitely filling up even when it was selected. This morning I swapped the fuel reservoir with a spare I picked after hearing they were no longer being made.

Wallah! I'm finally able to run off the front tank and can see the fuel level lowering. Although I can switch to the rear tank and the gauge works I haven't been able to drive it enough to tell if it is working correctly or not. Time will tell but right now I'm pretty confident I can run off both tanks for the first time since I've owned the truck.

Interestingly after swapping out the fuel reservoir the fuel filter whine dissappeared. I sure hope it stays that way.

Roy