I have a 97 3500 CTD cab/chassis. I just turned 454,000 miles. Recently I have noticed the smell of raw diesel fuel on the outside of the truck. My first thought was a leaking injector. That occured on my 92 250 CTD however when I popped the hood there really was no sign of any leaks nor was the smell detectable. I crawled under the truck and there was some fuel dripping from the bottom of the fuel tank. I dried it off and let it sit overnight. The next morning I checked the bottom of the fuel tank and it was still dry. There are however little drops of fuel on the ground on both the passenger and drivers side behind the cab like it had been dripping off of the frame. No leaks underneath motor. No problems with performance or starting as of yet in fact fuel mileage has even increased some. I am not mechanically inclined enough to fix this myself but was just wondering what you all think it could be and how much I might expect to pay to get it fixed. My gut instinct is it may be a fuel line since it appears to be a high pressure leak. Thanks one and all for the replies.

 

I know I have heard that the fuel lines on your era of truck deteriorate over time, so new fuel lines is what you need.

 

I would guess the rubber lines under the cab are shot. the section by the Bell housing where they connect to the metal section and between the tank are problem children. Mine were just dripping and the strong smell of diesel was there. Mine were just so dryrotted they were seeping over a 1' section.