Prius topped off gas by the gas attendant...

Punish the station owner/s clowns you mean, who are responsible for having the equipment maintained and repaired, or deactivated until the equipment is made serviceable again. The kid worked, the shut-off did not.

 

Yes. Exactly.

 

The problem IS that the canister is designed to purge VAPORS and not liquid.
Usually once it gets filled it STAYS full until there is some manual intervention.
Sometimes the engine runs badly and almost always it triggers a "check engine" condition.

A few people have been able to dis-assemble the thing and dry it out and keep going......but it is not made
to be taken apart and that process is kind of iffy. Others have ruined it and had to get a new one anyway.
I don't think those reports came from this forum though.

 

My first thought is "are you crazy?" There's liquid-phase carbon and vapor-phase carbon. If you flood vapor-phase carbon with liquid, I think it's ruined. But "I think", so to google I went for some answers. I didn't find a reference for why the two types of GAC aren't interchangeable, but I did find a very interesting side note from a book on Activated Carbon Adsorption:

That's cool. I still think you run the risk of ruining your carbon canister if you flood it with gas.

 

I suspect the underlying reason for topping up to the neck, and it's counterpart: running the tank near dry, is the quest for bragging rights for miles per tank. Either that or the belief that topping up is the only way to get accurate mpg calc's.

To each their own I guess.

 

Gas tanks and Evap systems vary greatly between cars. My 2001 Prius has a bladder and could regurgitate more than a couple drops if I accidentally overfilled. Seeing 10 miles of fuel belch from the tank is not fun. The manual also had specific language to avoid overfilling. I'm willing to bet that overfilling a bladder based fuel tank can force quite a bit of fuel into the Evap system.

My 2010 Prius does not have a bladder and behaves much more tamely on overfilling. Much fewer worries as the overfilling problem is solved immediately as soon as you start driving.

 

Filled the Prius on Sunday. Went to first auto shut off and then clicked in a little more to next shut off. As long as you're gonna drive a few miles right after filling the car, I don't think you will end up with liquid fuel in the canister. If you fill to the top of the neck and then park the car in warming weather before driving it and not actually using up some fuel, you will probably have a problem as the fuel expands.

I haven't filled our Prius to the top of the fuel neck. Why risk a spill?

 

On our 2010 Prius when filling the tank on slow speed once the auto clicks off you can still nurse about
2.1 gallons in the tank until you can see standing fuel at the top of the filler neck. This will increase your range 90-110 miles. I have only done this a few times and my check engine light never came on. Over 112,000 miles on
the car now.

 

Lucky so far.

 

It's not luck, and it will not hurt anything on a GEN III Prius. Find one irrefutable case where a "serviceable" GEN III had canister damage caused by topping-off. No one is telling others to top-off or not, but I am saying it won't hurt anything if you do. Do what you want.

 

It is ? Really ? Exactly how does that happen ??

I think you are mistaken.

A system designed to capture as many gas FUMES as possible certainly will not spit liquid gas OUT at any time, for any reason.

Quite to the contrary, I and many others are saying to NOT do it.

The owners manual says to NOT do it.

Owners of other models have learned an expensive lesson.......and I think a couple of Prius owners too.

What actual reference do YOU have that the system is designed so that damage will not occur when overfilling repeatedly ??
If you are going to "buck the tide" here you should at least offer something more substantial than personal experience or a gut feeling.

 

I'll try to be clearer. The 2001 Prius fuel tank had a bladder. On overfilling it would cause quite a lot of fuel to come out of the tank even after the nozzle was removed. There clearly was an "elastic" behavior. This is not rumor, but with over 13 years (and counting) of fillups it happened to me a handful of times. Either the nozzle did not shutoff normally or when I tried to top off when I first got the car. I definitely don't try to top it off for that reason and watch out for nozzles that might not shutoff. After shoving the gas cap on to stop fuel from continuing to dribble out, it would not be unreasonable to assume the bladder might have kept the tank "topped off" for some driving time after the fillup as the bladder contracted. Since this topping off put fuel above the access hole leading to the EVAP system, I could see how problems might be induced if maintained for too long. I could be wrong on that, but the vapor recover piping is put as high as possible for a reason.

Meanwhile the 2010 Prius does not have a bladder and behaves exactly like filling up every other car I have owned other than the 2001. It would not be unreasonable to assume that the fuel level in the tank starts dropping as soon as fuel is being consumed.

Nothing more or less was intended in the post.

 

OK but it won't drop much or very quickly.
If you get 60 MPG, then it would take about 7.5 miles to consume a pint.
I hardly think that qualifies as "immediately".

And the ones with the bladder business are kind of odd ducks.
Most of them might not even HAVE vapor recovery systems.

 

Easy Rider...again trying to measure manhood...and play the politician with partial quotes. As one old man to another, go find someone else to play with. You're just another yap dog.

 

It's pretty sad when you have nothing else useful to say and instead start throwing out personal insults.

 

Personal insults aside, I had problems with my 2007 Prius on only one fill up. Also the 2010 Prius manual still says not to top off the tank and my 2014 Prius Plugin says the same. Not worth it to me since the pain in the nice person I had with my 2007!!!!!!!!!!!!!!!!!!

 

Personal insults aside, I had problems with my 2007 Prius on only one fill up. Also the 2010 Prius manual still says not to top off the tank and my 2014 Prius Plugin says the same. Not worth it to me since the pain in the nice person I had with my 2007!!!!!!!!!!!!!!!!!!