i know this subject has been brought up before...but i couldnt find the answer i needed. i have the 4.9 with dual tanks. i cant remember the last time i had gas in the rear tank, and when the switch is on rear, the gauge goes down to empty, so i filled up the front tank today, but then switched it to the rear and drove for about 70 miles. i then noticed that the gas had been coming from the front tank all along (regardless of the switch position), and not the rear tank. so does this mean that the selector device is just stuck? can you get it from autozone? is it an easy fix? thanks.

 

I had two issues with the tanks on my '88 F-150. One was gas pouring out of the front tank, and the other was exactly the same problem you're having.

A new check valve fixed both my problems. My understanding is that Ford uses only one fuel pump for both tanks, and the switch on the dash sends a signal to the check valve to open either the front or rear tank for use. My total cost for the repair was $120.00.

 

heres another question, im looking through the haynes manual and it says that trucks with dual tanks can either have the "dual function reservoir" type system or the "shuttle selector valve" system. how can i tell which system my 89 is??

 

Give a call to a ford dealer parts department (better yet visit them in person) with your vin number handy.
They should be able to tell you which one you have, assuming original oem
parts are still on the truck.
Some ford parts services sponsoring this side (see listing on left panel) might also be able to help.
You might also consider investing in a good Ford FSM for your year and model.

 

is there something i can look for on the truck to immediately tell me?