Truth or myth?

Is it true that topping off your tank when refilling will ruin the gas sensor on a 4Runner? Is a little over a bad thing or once that chunk happens to pull it?

 

it’s best to stop filling at first click. Over filling gas tank can cause a couple of issues, including rupturing

 

It can introduce raw fuel into your EVAP system and cause issues. That's with any vehicle on the road with EVAP.

I fill until it clicks, wait 10 or so seconds and fill again until it clicks. That's it.

 

^^^

This is the correct answer.

Don't continue filling it after that. The cost of your repair is not worth it!

 

Some guys really need than .1 Gallon more to top it off?

 

I like the 10 second part, I fill until it clicks and then fill again til clicks again then done.

 

I fill to first click, done. Every time. That keeps my calculations based on the same process. YMMV.

 

I never overfill. The amount of fuel after the first click is negligible. Why even bother ?

 

Dam I've been over filling for years!!! Not gonna anymore!

 

Thanks all!

 

I overfilled mine badly one time. It didn't come back out of the filler neck but I'm sure it overflowed the evap system. I smelled gas for probably 20 minutes from inside the truck while I was driving. Lesson learned, never filling past the first click again.

 

Does anyone have an evap system diagram for the 5th Gen? I’ve seen two versions. One has a single small line from the filler neck to the high point on the tank (this prevents the glug-glug as the tank is filled). The other has the same line, plus a second small line that runs from the filler neck to the canister. Which do we have? Or is it different from both of those?

And if it’s the second style, and over-filling means sending liquid fuel to the charcoal canister, wouldn’t driving the vehicle tend to draw off the evaporating fuel from the canister over time and resolve the issue?

 

You just never know when you might need that extra hundred yards.

 

This is correct.
While on the subject, you should fill as slow as possible. While pumping slow, the pump reads closest to the actual fuel transferred.

 

In the 4Runner that’s feet, other vehicles it’s miles. Seriously 1/10 of a gallon is a more than a mile, but under 2.

 

After quick web search, if you overfill you run the risk of the fuel expanding beyond the expansion zone and filling your evap system.
https://www.motorvaps.co.za/blog/fill-up-to-the-first-click/
Edited to add:
You may not even get the fuel the pump tries to pump. This article says the pump can suck it back up.
https://www.motor1.com/news/298622/stop-fueling-up-pump-off/

 

A lot of coulds and mays and probablys in those articles. I don’t typically go past the first click anyway, but I’d be interested in having a crisp understanding of the situation.

 

So like this threads, no clear answer. In my younger days, I filled till the brim, currently it’s one extra click. Probably will just click it and finish in the future.

 

The funny thing about this whole subject… it’s only going to matter when you’re at the point of running out of gas. Which we never do, for the most part.

And that rare occasion that you do run out of gas? Pumping beyond the first click isn’t likely to have saved you anyway.

Isn’t it also bad to run with the gas tank at a very low level? It’s hard on the fuel pump or something? Because of that, I always fill up when I’m just under 3/4 of a tank. So, filling up past the first click is kind of a non-issue.

Now, if you’re OCD and need the pump to read a nice, even dollar amount at the end, well that’s a whole new thread entirely.

 

I give it 15 clicks then consider it good

 

Really? 3/4?

 

Yep

 

One day years ago I was filling my 2001. I would always squeeze in as much as I could when I was getting a fuel discount ($1/gallon). Well, this time I saw gas pouring out on the ground from the top of the tank. Turns out the frequent overfilling must have eroded/damaged the filler neck fitting. Now, it's first click only for me. And not right before getting home, either. I want to drive a bit after filling to ensure there's no gas in the filler neck.

 

Man, that would be filling up every day on most days for me lol.

 

That just seems to be needlessly hauling around extra weight all the time. I like to feel like I get some advantage out of a tank that doesn't weigh as much as when full.

 

Yep. When my 4R gets down below 1/8 tank, it's like I added a turbo lol.

 

lol. Maybe that explains why I think on some days I get better mpg than others. Never bothered to correlate fuel level with mpg, but maybe I should.

 

OP. Dont do it! Stop! It will certainly break it!! It’s worst if you do it to a Tacoma or Corolla. Def don’t on a 4Runner

 

My answer (which will be wrong for some) is if I'm on a road trip I fill it up then a little bit more as I know I'll be sucking the tank done while continuing on my trip. For around town normal stuff I generally will stop at the first click, especially during summer temps as fuel expands fairly quick and it needs space in the tank...

 

Haha I just realized I mis-spoke. I meant when I’m down to 1/4 tank left. In my head I was thinking “3/4 of a tank down”.