Hello, I would like to explain my recent problem with my 93 F-150 4x4 5.0L manual 5spd. I was driving home from up North last weekend and filled the rear tank full, then 20 miles later on freeway it cuts out completely, so I spent 1hr puttsin, and decided to try selecting the fuel tank switch to the front tank position and it fired up, got me home 90 miles no prob. Never had a problem before with the rear tank, but the front tank does leak fuel past about 1/2 full, leaks at the mid-seam. Last eve. in driveway, I started it up in front tank position, the after 10 min idiling switched to rear tank position and did not kill at all, ran fine for 10 min till I shut her down. Now I am thinking both pumps still do work. The rear tank does go down bit fast on fuel level, but I did notice from searching yesterday on similular problems that the return lines can pump into the other tanks. I could have a bad front check valve? The point is I need to go back up north this weekend to build my deer stand, and wonder if I am going to get stranted with guns and a dog. Any Ideas to check, or just drive it and if dies switch to other tank quick and hope for the best? P.S. I have changed about all the sensors / injectors on this engine, nearly everything is new.....except the EGR stuff. Thanks, Doug