Help a newbie! Has anyone ever experienced a small leaking of gas from the adapter right after fueling. A cabbie that was filling next to me told me that debris might be caught in the adapter holding it open. It's not a large amount but I can hear it hissing and smell it too. I can place my finger over it and feel the pressure as it leaks out. Doesn't drain the tank and seems to stop by itself but just curios.
Is this something that is common or am I in grave danger and should I zoom over to my local dealer and have it looked at right away ?
My 96 was leaking and even the frame was wet of fuel after a full refill.
I replaced the fuel tank, which was quite rusted and it was still leaking after filling-up.
I found my problem:
There is a vent tube connecting the top of the tank to the filler neck. The hose connecting those 2 things is made from plastic. It's similar to the black plastic tubes they use to cover the electrical wires. It's very cheap, and mine was cracked. When I filled the tank too much, fuel was leaking from that tube. I went to the garage and they tried to fix it the best they could by replacing that stupid plastic hose for something better, but they failed to repair it. They would need to remove the tank and to create a custom hose, in metal, to replace completely the pastic one.
Maybe the source of your problem is similar to mine?
I wouldn't say 'grave danger', but I would find a local dealer with a CNG Systems trained tech (which you may have to hunt a bit for) and get it checked out. And between now and when the replacement part comes in, park outside - not near the water heater in your garage. Pilot lights, yanno. ;-)
There are bound to be multiple check valves in the system, since redundancy is a good thing at 3,000 PSI - the check valve in the CNG fueling fitting is leaking, but the one behind it (probably at the tank) holds, because as you said as soon as the pressure in that section of hose line bleeds off it seems to stop.
SAFETY NOTE: I seem to recall something about the fuel tanks having a finite life cycle - a 12 or 15 year expiration date. They're fairly thin aluminum (3/8"?) with a fiberglass reinforcement wrap, and eventually the aluminum fatigues and cracks and you have /real/ big problems... Which is why they want to pull the tanks from service and replace them before they get that old.
Don't be surprised if the properly trained dealer technician brings this up, matter of fact I'd be surprised if they /don't/. You may need to take the money you are saving on gasoline and maintenance and bank it toward a fresh tank in another few years.
SuperShuttle had one of their CNG Vans go BOOM! (no flames, just the gas release) a few weeks back because of an older tank failure, since they drive the wheels off they get fueled daily at least, and the tank had a whole lotta fueling cycles on it. And the vehicle was fresh out of the shop after a rear-end collision that may have damaged the tank
- but no word on if they checked it, or even knew how... Killed the driver, shrapnel.
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I wouldn't have responded at all, but for...
What part of the word CNG in the header did you miss? >.<
That stands for Compressed Natural Gas, not Gasoline. Totally different fuel, totally different fueling systems. If the OP has got any sort of liquid fuel on the frame he's in BIG trouble... ;-)
This van fuel tank exploded on the first fuel fill after getting it out of the body shop for the rear-end collision damage. I wouldn't have been standing right there during the fueling cycle, I know better
- but most people don't.
And the sad part is, as an "independent contractor", the victim owned the van. Even if someone said "The tank could have been damaged in the wreck, should we replace it?" the next question would have been "The insurance company says they won't pay for them - Can you afford a new set of tanks, and another two weeks of downtime while we get them installed?" Safety would get skipped in the chase for the Almighty Dollar.
It's the tank technology - the fiber reinforced idea is great ONLY as long as the fibers aren't disturbed, and they get disturbed way too easily on a road vehicle. Get in a minor accident, drive over road debris... If the fibers were not there, the inner aluminum tank would not survive the initial hydro-test without gross failure.
And the tanks having a fixed expiration date where they must be replaced is only a good safety measure if there is a mechanism to enforce it, and they refuse to sell fuel to people with expired tanks or even refuse to issue annual registration. Since these can be fueled with a compressor at home or at work, that won't force the change, and you will see more of these failures.
Then you'll get crooks who try to make new fake date tags for old CNG tanks and charge for installing a new set and disposing of the old, just like 'Spiffy Lube' (name changed to protect the author) charges for work they don't perform...
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