I've searched high and low on these forums and across the net for another mention of this problem and come up empty handed so far. Awhile back I started noticing a gas smell when i filled the tank. Thought it was spilled fuel at first, but the smell would come back after driving but dissipate when it sat for awhile. I was parked heading downhill on a steep driveway and it actually was dripping from the front of the tank. If I fill the tank and drive in tight right-hand circles it will leak quite a bit also.

I used a procedure elsewhere in this site to drop the front of the tank to get a decent look at the front vapor recovery fitting. The tank was about half full and if I rocked it up and down I could get it to slosh enough for the white plastic part to get slightly wet with gas, but not enough to soak the area or locate the leak. I removed the vapor line and plugged the tube extending from the fitting and rocked the tank again. The area got a bit wet, but not near as much as with the hose connected. Not conclusive enough to confirm or eliminate the fitting seals, but suspicious.

Has anyone else ever experienced a fuel leak from the front vapor recovery area? Was it the hose, fitting, or the connector on the tank?

I can fill the tank almost full and repeat the tank drop exercise (oh what fun), but wanted to check to see if anyone else had any experience with this specific problem.

Also, I have been unable to locate a source for a replacement tank fitting, or even a exploded drawing that identifies the fitting. So far, the closest I have come is the vapor hose assembly that connects to the fitting. Any help here is appreciated. Thanks!!

 

I have had luck finding leaks with a smoke machine . So , if you have an extra grand and change buy one . But seriously , If you put slight air pressure in the tank through the fill cap location , you can find a lot of leaks . Stuff a air blower wrapped with a rag into the fill neck . Turn the air down to 20psi or so and apply pressure . Have a friend help and listen and look for leaks . A piece of hose held to the ear and moved around suspect areas can help . Just a thought !

 

Could be one of the hoses ontop of the tank. I had to replace the filler hose on my brothers Ranger because the stupid filler/vent hose cracked. But it was a known issue on them. I haven't really heard of any "known" fuel tank issues with the Expeditions. Anyway you can look up the parts to get an idea of what to look for here: Buy 2003 Ford Expedition Parts | FordParts.com. Or if you have a bore-scope type camera you can fish it around up there and take a look. The Ridgid Borescope is available at most Home Depots for about $200.



-Mike

 

Thanks. A commercial smoke machine is not in the picture, nor is the $200 most shops want to use theirs. A search on YouTube yielded a plethora of handy home made versions.

That is my next step it seems.

 

Thanks. I stuck a name badge magnet to my iPhone and stuck it to the underbody above the tank. Fired up the FaceTime app and the picture showed up on the iPad. $800 worth of Apple products to see in tight spaces, but hey, they have other uses too! Also good for getting a look at tight spaces around the house.

 

You're the type of guy that makes women nervous!

 

I have the same exact problem. Just started noticing the leak, checked and found the leak is from the base of the vent valve. Thinking to lower the tank a little and apply a very good fuel tank sealant around the base and if that doesn't work then I guess it's a new fuel tank since they don't sell the valve by itself. Now maybe you can help me with instructions on how to lower at least the front side of the fuel tank so I can see the vent valve directly instead of with an inspection mirror. Tks.....

 

I would lower it level, for safety reasons. You don't want it sliding off your jack.

 

alkadeem, I was never able to view the fitting area directly without removing the tank completely. I discovered a clever inspection technique that has worked even where inspection mirrors failed - an iPhone using FaceTime. I have an iPad and I connect the two using FaceTime, using the phone as the camera and the iPad as the view screen. You need to quickly mute both microphones as they will feedback and it's not pleasant.They have video inspection tools by they are a bit pricey for the home mechanic. I dropped the tank enough to get some light onto the subject and held the phone close to the fitting.

I could see that there was a small split in the gray plastic fitting. The split started near the center of the fitting and went out to the outer edge. The fitting is not replaceable since it is "welded" onto the tank body. Once I found the crack I resolved that the tank needed to be dropped to do the repair. It could have possibly be repaired in place, but the chance of an bad repair outweighed the trouble of dropping the tank.

Be forwarned - dropping the tank takes patience, nimble and flexible hands, and some good instructions. I subscribe to Alldata DIY (best investment I've made) and their instructions are quite detailed for a tank drop. And it also takes a nearly empty tank. You have to lower, move, slide, drop, and fiddle with connection all along the way and with more than a few gallons in the tank would be difficult and likely rip off one of the many connections. I used two floor jacks with a 2 foot square of plywood on top of the main jack as a support. You have to spread out the pressure or risk damaging the pump and pickup inside.

I used JB Weld to seal the crack and, knock on wood, it is still holding after all these years. One thing I would do different is to replace as many of the vapor lines as possible while I was in there. It now throws a "very small vapor leak" error about every 600-800 miles and I suspect one of those vapor lines on the top of the tank. Also the pressure sensor inline connector on the top of the tank, near the rear, was very difficult to get reconnected. You have to get it to "snap" together or the connection will be intermittent and set off your Check Engine light every time.

Good luck with the project! It is doable but a bit challenging. I also highly recommend JB Weld two part epoxy adhesive. Thousands of farmers can't be wrong...the stuff is incredible.