How bad is lowering a full gas tank?

[gimlithepirate]

I need to replace my fuel float (and while I'm at it my pump), which means dropping the tank. However, the tank is currently mostly full. How horrible is lowering the tank with it mostly full? I guess I could put off the repair a week and try to run the tank out, but since I don't know the gas level that feels a tad dicey.

 

[MikeinNH67]

With the shape of the tank I would wait until it's closer to empty or siphon some out.

 

[Inv4drZm]

Something you could do, which I've never tried, is disconnecting your fuel return line. In front of the tank there's a plastic elbow. There might be another connection around the fuel rail too, but empty it into a bucket while the vehicle is idling. I'm not sure how long this would take.

Fuel weighs roughly 6lbs per gallon so a full tank would be around 120lbs. You could lower it slowly with a floor jack, but I've wrestled with a fuel tank before and it's hard to align when empty. Could also try lowering when full, then empty it and reinstall. Then pour your fuel back in.

 

[thennen]

You could take a gallon can of fuel with you each time you drive it, then if you run empty, just put that in (plus a measured amount at a gas station if needed to get you home). Then at least you know you’re almost empty when you drop it.

My 1984 Supra had a drain plug that I used one time. I guess that’s not the case with 4Runners?

 

[Warwicke36]

They slosh back and force some thing awful. I just did one in and Escalade with a 26 gallon tank. I got all but about 5 or 6 gallons out (it was Full when I started on it)... I have a transmission jack mind you... Getting it down wasn't so bad. Hut getting it off the ground back onto the tranny jack by myself was brutal. I nearly dropped it a few times before finding a better way.. To get it up there. If you have access to 2 Jack's that would help.


When I did mine in my 4runner I had a pretty full tank... But I was just replacing the straps so I never lowered it down at all.

Get a hand pump siphon, they're super cheap. And have some gas cans ready...

Here's me doing the escalade with a siphon..

 

[AuSeeker]

I would run as much gas out that you feel safe doing, if you know the MPG you get you should be able to estimate good enough to still have 3 to 4 gallons left in the tank, but I would try and get it even lower and have a 5 gallon can of gas on hand for after you finish the job and or if you happen to run it out of gas you could put a gallon or so in to get you home or where you plan on doing the work.

Gas weights 6.1 lbs per gallon, so with a full 23 gallons in the tank so that's 140 lbs plus the weight of the tank so at least 150 to 160 lbs and with the gas moving within the tank you would have BIG job keeping it under control and if it falls off the jack you could risk a bad injury if it falls on you

 

[Unner]

Lowering a not full tank of gas sucks, lowering a full one sucks more. I'd try and get it as low as you can like the other said. But, I also understand that isn't always possible if you have time constraints. If you're careful and have the right equipment there's no reason you can't lower a full tank. It's just gonna be worse.