Problem filling the tank!

[ahfox]

Has anyone had a problem filling their motorhome at the gas pump? Can not seem to figure out why it is taking forever to fill up with the nozzle shutting off at the pump due to the constant backing up of the gas; almost as if there is an "airlock" or something. The mechanic at the Chevy garage says everything checks out OK electronically, but I got the impression he did not want to really deal with it. My money is green, but maybe his expertise in this area was limited!

[cgmartine]

In some cars, that is sometimes a sign of a bad evaporator canister. This is a canister full of charcoal which is intended to catch the fumes that are not ingested by the engine so that they are not vented into the atmosphere. When the canister is full of crud, or one of the check valves goes bad, the fumes no longer go into the canister, but back up the filler tube. It is this back up which causes the slow input of gas into the filler tube. I am not saying this the problem with your motorhome, but if you have such a canister, it is something to consider.

[BruceMc]

We've had our 24' Sunseeker on Chevy for a year & 1/2 now; I had never experienced the issue until I filled up at a station in Arco, Idaho during our recent 3800+ mile trip. After the first couple of gallons, I was ready to shut it off & move to another pump. I stuck with it for 25ish gallons. Never had the problem since, so I attribute that one to an overly sensitive nozzle.

If the issue has happened at another time, it was during a fill in Oregon where state law requires an attendant fill the tank if filling with gas. Drivers can fill their own tank if the fuel is diesel. I've never heard anyone complain about it, so I suspect it hasn't happened to an attendant.

What feels odd is that I filled my tank for 2 weeks on this trip, then after pulling into Ontario Oregon, I had to resist that urge.... but I still had to clean my own windshield!

(Oregon, Washington, Idaho, Montana/Alberta - Glacier/Waterton, Wyoming, Colorado, Wyoming (family reunion), Idaho, Oregon)

[IAMICHABOD]

.

[robrv3]

I had problems filling my tank took forever cause the nozzle kept shutting off no mater how I held the pump handle I could put gas in one squirt at a time I experienced this at 2 gas stations. The gas stations I normally use near my house are okay except I need to lift the handle up otherwise I can pump at full speed. So for me its a pump dependent issue to me the tub from the gas cap to the tank seems awfully narrow about 1", must be part of the issue.

[Snowman9000]

Our Chevy Class C was fine, until it wasn't. Then it would barely take gas without shutting off. Then the next trip, after sitting several months, it was fine again. I decided it happened from topping off, and messing up the canister. So, no more topping off. So far so good.

I do seem to have to turn the nozzle to the side a bit, in any case.

[Bordercollie]

This fueling problem, water leaks, short rubber valve stems on tires and seat belts for passengers have been problems for RV owners for many years. We will probably be putting up with these issues for many more years

[Robocop]

Interesting. And here I thought it was just me. For the first 5 years/15,000, no issues. More recently, almost every fill up. I slow the fill pace down, turn the nozzle upside down, etc. and for the most part once there is a steady draw all is fine. I figured it was a vapor lock issue but not sure how to address it. Good info.

[Stefonius]

ahfox wrote:
Thanks for all the suggestions. I just heard back from the seller saying he took the unit to another garage and they supposedly diagnosed the problem due to something called the canister. I wish I was more up to speed on such, but I really have no idea what the canister does or why it 's demise would effect the filling of the tank???
Keith

The canister is basically similar to a coffee can filled with activated charcoal pellets. It sits in line with the fuel tank vent and captures fuel vapor, which is then drawn out again during engine operation. They've been on vehicles since the late 60s or early 70s, and are there to stop gasoline vapor from venting to the atmosphere.

If a system is overfilled with fuel (or has any of a select few other problems), liquid gasoline can get into the canister and turn the charcoal pellets into something resembling black concrete. Once that happens, the tank won't vent air properly as fuel is added.

Does that help?

[Campincarters]

Just to let you know I was getting error codes also but once the angle was corrected it all went away. This is a common issue on chevy chassis from what I learned.

[ahfox]

Thanks again! I can not believe how helpful and fantastic this forum is!!! I hope I don't wear out my welcome with so many questions. I am just so new at this RV game and I am starting off with a used unit. Probably a mistake fora "newbe"

[cgmartine]

Ok. I guess I missed your lat posting of 12:34 p.m. As I suspected, most likely it is the canister, but I would also suspect the valve,which opens and closes to allow tank gases to exit the tank and into the canister. Either one would cause the condition you described, however, there may be other conditions/components. Have a parts store use a scanner to read for any codes. The codes will tell you exactly the problem location. By the way, the canister is located next to the gas tank in some vehicles. Some are easy to get to, some are not. The valve is attached to the canister.

[cgmartine]

Actually, the term "electronically," may not be too far off. The mechanic may be talking about a EBDT code (hope I got the acronym correct). You can read these codes with a scan reader. If your engine displays the icon of "service engine" soon, it may indicate a code related to the gas tank vaccum valve or canister, which filters gas tank gases before allowing them to escape from the gas tank and re-routes them to the engine so that the gas tank does not vent gasses into the athmosphere. When the check valve goes bad, it causes a problem when trying to deliver gas to the gas tank.

[ahfox]

Thanks for all the suggestions. I just heard back from the seller saying he took the unit to another garage and they supposedly diagnosed the problem due to something called the canister. I wish I was more up to speed on such, but I really have no idea what the canister does or why it 's demise would effect the filling of the tank???
Keith

[Campincarters]

I had the same issue. I had to go to a truck mechanic who was able to get my C in the air. The filler hose had a uphill section. They did some adjusting and everything was fine. Cost me about 300 to 400 but I can put gas in with no problem now.