Here's my advice on this subject. My 99 Tahoe LT 4WD had similar problems. The fuel pump inside failed (of course it was just I after I filled her up!) and the neck had a crack in it. It wasn't a constant leak, but sometimes when I refueled it leaked like a sieve. So I take her to my mechanic, who retired and closed shop around a year later, says that he can use/transfer the parts from inside the old tank to the new one. And it would have saved me a hole mess of green if I did, but I'm old school and I told him to change everything and let's start new. He pointed out that my 99 Tahoe (145K mi.) was 16 years old but in the prime of life. So I went with his decision, which turned out to be a big mistake. The fuel sensors in the tank went out around 1k miles later and my gauge would only read full, so I never knew if I was going to run out of gas. I used the trip meter to estimate the MPG and would fill up accordingly. It was a pain in the ass. Worst yet it ended up costing me more to have it repaired the second time than the first. The moral of the story (I guess) is the sensors and components, which are made of plastic & cheap aluminum, are submerged in a tank of caustic liquid (gasoline) 24/7 and if the tank is leaking it may be a sign of what's going on inside the tank. Thought of that after the second repair as I was trying to figure out how to pay for it. Hindsight is 20/20! Go figure!
