Is it harmful to top off your tank?

[Archosman]

Was at the dealer today and only heard part of this conversation. One of the service guys was telling a woman that when she fills up as soon as the pump handle clicks don't fill it up anymore. Said it can damage a vacuum line. When I fill up as soon as it clicks off I'll put $1 worth in. Is this a bad thing?

[zppeacock]

It can get into the lines to the canister. Just dont go crazy when filling up.

[somick]

When you overflow the tank the gas is routed to the canister. When canister is full the gas goes down on the floor. You often cannot see it because it is underneath of your car.

Keep pumping it! Gas is cheap.... Parts are cheap too...

[Archosman]

Had no idea. I'll be more careful from now on.

[PhatRoyale]

I usually stop when it clicks.

[tengiday]

Sorry, for a few stupid questions. I always pay before filling gas, and when it clicks, I still have the money for 1/2-1 gal more. Should I keep fill more or stop? How about the money left?
I also notice that when I top off the tank, the fuel gauge sensor stays at full until I have driven about 40+ miles. The sensor goes down quickly when I have about 3/4 full. Is it normal?

Thank you!

[judge34411]

Originally Posted by tengiday

Sorry, for a few stupid questions. I always pay before filling gas, and when it clicks, I still have the money for 1/2-1 gal more. Should I keep fill more or stop? How about the money left?
I also notice that when I top off the tank, the fuel gauge sensor stays at full until I have driven about 40+ miles. The sensor goes down quickly when I have about 3/4 full. Is it normal?

Thank you!

Only stupid question is the one you do not ask

Get the money back, its yours. Even if it is only 50 cents. As for the drive 40+ that is normal on most cars to one extent on another. On my diesel I would drive at least 100 miles before the gauge showed a drop. On this Camry I have now I only see it after about 30 miles. It is just head space over the top of the float in the tank. The gauges are only approximate. An actually I imagine when it hits 1/4 of a tank it seams to go down faster than it does at 3/4. Again very normal. An to be frank you really should be thinking of topping off when you see just under 1/4 because if you start to let it suck at the bottom you can be picking up lots of junk in the bottom of the tank. Not good for the fuel filter.

[dvp59]

Yes it can also damage the fuel pump on some of these cars. It uses the gasoline for cooling..Low tank equals more heating...plus bumping the fuel to overfill the tank does cause Emission controls and canister problems..D.