Syphoning old gas
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Ign
Well-known member
Not exactly, just using the Venturi principle?
Don1357
Well-known member
I would risk to guess that the car had a mechanical fuel pump, meaning that it it ain't running it ain't pumping gas. I guess you have two options: to either pressurize the tank so it will push the gas out of the hose, or you could spend $20 on a cheap fuel pump and drain the tank with it.
Meursault74
Well-known member
Syphoning old gas............. made me think of this Cheech and Chong scene.... now that's some old gas ;-)
kythri
Well-known member
I've had great luck with the "Super Easy Siphon Hose" that I found on Amazon:
https://www.amazon.com/gp/product/B00MVAIL76/?tag=atomicindus08-20
Absolutely love this thing, makes siphoning gas or anything else a breeze.
https://www.amazon.com/gp/product/B00MVAIL76/?tag=atomicindus08-20
Absolutely love this thing, makes siphoning gas or anything else a breeze.
The jerk me hose, they do work well as long as you have a few inches of liquid.
jonesg
Well-known member
Any hardware store selling kerosene heaters will have the $3 siphon pump.
https://www.tractorsupply.com/tsc/p...JgtItg13xqPbz_cwRGyVkYNZHFYMXkJ0aAqQJEALw_wcB
https://www.tractorsupply.com/tsc/p...JgtItg13xqPbz_cwRGyVkYNZHFYMXkJ0aAqQJEALw_wcB
fsae0607
Well-known member
You're not a true gearhead until you've mouth-siphoned gas and gotten a mouthful! 
But seriously the jerk hose or this works great:
https://www.harborfreight.com/Fluid-Siphon-Pump-62613.html
I have the HF one and it works great.
But seriously the jerk hose or this works great:
https://www.harborfreight.com/Fluid-Siphon-Pump-62613.html
I have the HF one and it works great.
SeisMec
Well-known member
Have siphoned gas, diesel & hyd. fluid many times using a hose, blow gun and a rag. Hose into the tank via filler neck - nozzle of gun into filler neck - stuff rags into filler neck - palm of hand over it all to seal as best you can . A one or two second long shot of air starts the siphon.
DugT
Well-known member
I wish I would have thought or heard of that decades ago.
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driz
Well-known member
Those 1/2” jerker hoses are great. I’ve had the same one over 20 years. I’ve pumped thousands of gallons into my boat and tractors.. When the hose gets too stiff from age just go buy 6-8’ of hose at the hardware store. The valve lasts forever. The only time these aren’t so great is if you are tiring to start it in a container with just a couple inches of fluid in it.
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3jakes
Well-known member
Ok, that sounds like a keeper.
But do not most cars since the "gas crisis" have an anti-siphon blockage spring thing?
Ign
Well-known member
I've got a jiggler, too, but that's what I've always heard it called: a jiggler. Learned that term from Bill Burke long ago during a Moab run.
driz
Well-known member
You’ll never get a giggler into a gas tank . Worse if you do it will likely never come back out again. To siphon dry an installed car tank you’re going to need the thinnest hose you can get from the hardware store. It’s slower than you’d like but at least works.
Use the cheap hard stuff that’s translucent not the clear soft hose. It’s tough enough that if it gets wedged inside you can get it back out without breaking it off . Some of those restrictors inside the bottom of the hose have sharp edges and act like a Chinese finger trap which is why I use the cheap hard pvc hose
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Use the cheap hard stuff that’s translucent not the clear soft hose. It’s tough enough that if it gets wedged inside you can get it back out without breaking it off . Some of those restrictors inside the bottom of the hose have sharp edges and act like a Chinese finger trap which is why I use the cheap hard pvc hose
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Skiff Builder
Well-known member
I sort of use your system but in a different way. 20' of 1/2" pex into tank of Yukon. Hold air hose parallel to other end of hose, (or finally drilled a 1/4" angled hole near end). Air flows, venturi, starts siphon. Filled boat many times from bulkhead this way.
Skiff
SeisMec
Well-known member
Anyone that's ever had a mouthful of fuel wishes they'd known some other way. Wanted to kick myself the first time I saw this done.
Parrothead
Well-known member
You're not a true gearhead until you've mouth-siphoned gas and gotten a mouthful!
But seriously the jerk hose or this works great:
https://www.harborfreight.com/Fluid-Siphon-Pump-62613.html
I have the HF one and it works great.
An additional option.
https://www.harborfreight.com/multi-use-transfer-pump-63144.html
Good enough to pump 72 gallons of water... unfortunately
joe_padavano
Well-known member
I don't know about siphoning gas, but I've had a Vacula brake bleeder that uses the same venturi principle for decades. It's one of the best tool purchases I've ever made. As far as clearing old fuel from a tank, if you have compressed air, it's far easier to simply route the tank outlet pipe to a container and use compressed air at the filler neck to simply blow it out.
SeisMec
Well-known member
/EDIT: Saw Joe's post above after posting. In most cases that has to be a better, simpler solution than mine.
END EDIT:/
Most of the siphoning I've done this way was decades ago and mostly from bulk tanks or saddle tanks on large trucks. No anti-syphon on bulk tanks and tapered spiral springs in the filler neck of saddle tanks were (are?) so easily pried out as to be pointless.
Haven't syphoned fuel from a car or light truck that would not now be 20 or more years old. Presuming things haven't changed, disconnect the 2-3" diameter hose from the bottom of the filler neck inlet and syphon from there.
Re the "gas crisis" - started work in a service station after the first one. Must have disabled at least a hundred of those springs that customers had self installed and then discovered they couldn't siphon gas into their lawn mower. Brake spoon pried out the first bit. Large screw driver with rag padding the tip was used to leverage some more out. Needle nose vise grips to prevent the part you were going to cut off from falling in. 14" end nippers to cut the spring. Upper couple spirals of spring usually stayed in the filler neck. If customer had to have it removed, cussing usually ensued.
I don't know about siphoning gas, but I've had a Vacula brake bleeder that uses the same venturi principle for decades. It's one of the best tool purchases I've ever made. As far as clearing old fuel from a tank, if you have compressed air, it's far easier to simply route the tank outlet pipe to a container and use compressed air at the filler neck to simply blow it out.
Last week, I used my HF Brand one to siphon gas from a car in the garage that goes nowhere. I rotate the gas yearly and burn it in my daily driver. Only problem it is 1 quart at a time but I get it done.
ex-x-fire
Well-known member
https://www.garagejournal.com/forum/showthread.php?t=362083
I made this a few years ago and it work great for gas too.
I made this a few years ago and it work great for gas too.
Leaflessshadetree
Well-known member
I just use a plain section of hose and use my thumb on the end to be the valve.
Works just like the jerk type.
Seems like every time someone sees me do it they first tell me I'm stupid. Comment abpout a mouth full of gas. Then ask how gas can be flowing out of the hose?
Works just like the jerk type.
Seems like every time someone sees me do it they first tell me I'm stupid. Comment abpout a mouth full of gas. Then ask how gas can be flowing out of the hose?
![otc8100[1].jpg](/forum/data/attachments/873/873403-ba0508cef746ef8168f0bcfe6a0a55ff.jpg)
Ok, this is similar to what I have - mine is 15 yrs old. It displaces a lot of fluid per stroke..
richfinn
Well-known member
I don't know about siphoning gas, but I've had a Vacula brake bleeder that uses the same venturi principle for decades. It's one of the best tool purchases I've ever made. As far as clearing old fuel from a tank, if you have compressed air, it's far easier to simply route the tank outlet pipe to a container and use compressed air at the filler neck to simply blow it out.
I would advise against pressurising the fuel tank with compressed air, It will find any weak spots thats for sure
At worse you might blow a pipe off, at worst you could damage the fuel tank when it swells up and starts leaking (particularly old metal tanks), I've seen both happen
I like to bridge the fuel pump relay out (if it has an intank pump) and use my fuel pressure gauge kit to direct it into a container
No fuel pump, thin tubing works good down the filler neck and **** the fuel into a gas caddy
atikovi
Well-known member
Won't work in most cars after '74. The nozzle restrictor prevents entry, and if you bypass that, the rollover valve probably will too.
SeisMec
Well-known member
Siphon hose + air nozzle + shop rag with your hand over it all makes a very poor seal. A short (1 second) shot of air probably makes at most 10 psi in the tank - though I can't honestly say I've ever attempted to measure. Probably only done this on a couple of new style plastic tanks - maybe 50 or 60 times on old style sheet metal tanks. Never a problem. If 1 second produces a leaking tank would guess that an immanent failure was detected. Probably at a more convenient location than at some random spot along the road.
EDIT: Least anyone is confused. You're only using enough air to start the siphoning - NOT attempting to speed up the syphoning action with air pressure. That would be stupid and almost certainly blow hoses off or damage the tank.
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theoldwizard1
Well-known member
The new ones come with the hose pre-kinked ! Useless. Buy the end and buy your own hose.
theoldwizard1
Well-known member
A lot of new vehicles have some type of "trap door" that makes siphoning fuel difficult/impossible. The following trick works well on becks with filler necks, especially on tanks >5 gallons, if you have shop air or a really good set of lungs !
Insert the hose you are going to use for siphoning. Obviously it has to be long enough to go into the tank and below the liquid line and come out and into the receiving tank at a lower level. Insert a SECOND short, clean piece of house into the tank. Use rags to seal up the opening between the two hoses and the neck of the tank. BLOW HARD (use shop air).
Once the fluid get "over the hump" you are home free !
Insert the hose you are going to use for siphoning. Obviously it has to be long enough to go into the tank and below the liquid line and come out and into the receiving tank at a lower level. Insert a SECOND short, clean piece of house into the tank. Use rags to seal up the opening between the two hoses and the neck of the tank. BLOW HARD (use shop air).
Once the fluid get "over the hump" you are home free !