Seems like I have tried to slip a small nylon siphon hose down the tank filler tube and been blocked by baffling or whatever? I need to get about 10-15 gal of gas out of the tank, drop the tank, and do welding safely.

I’ll listen to any ideas. I took a look at fuel plumbing at the mechanical pump, and I see a 3/8” hose clamped to the pump. A filter just downstream of this connection. My bohemian brainstorm would be to remove this hose, ad a hose barb and three more feet of hose to a five gallon can. Then take a small shop vac and lightly pressurize the tank at the filler tube, pushing the gas into the 5 gal tank. I have dropped the tank before, replacing bad hardware, so dropping the tank is actually the easy part. Just all the gas is more weight than I can handle.

Bad idea? Good idea? Burn the Shop down idea?


Left side hose from the tank, at the engine pump. I think? Don’t know if this is a stock setup or been McGivered by a PO?

 

Remembered there are multiple tank vents on front edge of tank. Will need to disconnect and plug them. Otherwise would push a lot of gas vapor into the Shop, I think?

 

Disconnect the hose at the fuel pump and run it into a gas can. Use a rag to seal a compressed air nozzle to the filler neck. I can get about 90% of the gas out that way. The air compressor puts out enough air to let some bleed out the vents.

 

Thanks Joe. I just remember some kind of flaky vapor recovery system and don’t want to damage that. Should I just disconnect the vent hoses, or is it no big deal?

 

I did this on a 1985 and didn't damage the evap system. If you are worried, go under the car, disconnect the vent and return lines and plug them before emptying through the feed line. The feed line is the only one that is 3/8". The vents are 5/16 and the return is 1/4.

 

Another method, raise the back of the car enough to get it on stands, disconnect the rubber hose at the fuel pump, put a hole in the rubber hose angled toward the direction you'd like the fuel to flow, aim the hose into the container to catch the fuel, put compressed air into the angled hole with a blow gun and the fuel will start to flow due to the venturi effect.

 

I've done this in years past - works great but instead of an air compressor I used a canister vacuum cleaner w/ the hose plugged into the opposite end of the canister - worked like a charm.

 

I think you mean a different type blow gun? I'll grab a cookie on my way out the door...

 

If he hits ya with that thing, it’s gonna hurt. Save a cookie for me Norm.

 

If you are working with gasoline then don't do this.

 

Why not? Atomization of the gasoline?

 

Reason? That process is detailed in the factory CSM.

 

Please do not use ANY thing that has brushes in the electric motor to transfer gasoline.

 

I think the fuel tank would swell up and distort long before damage would be done to the other stuff.

 

I've used a rag around an air nozzle several times. Works well.

 

Please do elaborate, for those of us who do not have a CSM or have one memorized.

Is it because of the possibility of brushes in the compressor motor igniting vapors? (I would assume this would be done far enough away and with more than adequate ventilation to prevent this. Besides most compressor motors don't have or use brushes only at startup).

Or is it because of the potential for high-velocity air generating static electricity that may discharge and ignite the vapors? At work we were required to use extraordinary precautions to prevent static build-up to avoid latent damage to sensitive electronics. When using a vacuum cleaner to pickup debris near flight electronics, the (plastic) nozzle used was wrapped with copper tape that had a lead wire that grounded it. I could see a similar precaution in this scenario being used to prevent ESD.

I like the siphoning procedure best though.

 

^^^THIS^^^

No need to overthink this.

 

I have been known to read the Instructions last thing. Typical man I guess. Your method sounds about what I found in the Chassis Service Manual. Section 8 about page 28 or so.


I just remember trying to insert something into the tank, and not being able to do so. Was not a small copper line though



Venturi effect


Definitely a concern of mine. I am thinking Dealer service bays have no open flame devices anywhere. My Shop, on the other extreme is heated with a wood stove, just a few feet from the car.

Yea, looks like it.

Does not take a lot of air pressure to have this happen. I have seen poorly built aircraft tanks with accidentally blocked fuel vents that were bent up by air pressure

Tomorrow the tank is getting drained. Prob by Norms method. I’ll detail it for those interested.

 

If you can get a tube into the tank then get yourself a "Safety Siphon."

https://safetysiphon.net/collections/siphons

Otherwise follow the advice to gently pressurize the fuel tank at the filler neck and then collect the fuel from the rubber hose that has been disconnected from the fuel pump.

Running the car until the fuel tank is nearly empty also works well.

 

Sacrebleu ! Our Sacred Tome has given us some bad advice, No?

 

When I dropped the tank the first time to replace the fuel level sender, I did just what you said. Put a two gallon gas can in the trunk, and drove till I was out of gas. Put in enough to get home, and dropped the tank.

 

So I did get the tank nearly empty and removed it today. Bought 5 feet of 3/8” fuel hose and a splice barb to connect to the hose at the fuel pump. Then ran the hose beneath the car to gas cans in front of car. I thought that perhaps gas would come out without pressurizing the tank, but NO. I did raise the rear end of the car 5.5” to get enough room to slide the tank out. This put the bottom of the tank about 6” above the top of my 5 gal gas can. Once I pressurized for about 5 seconds with a shop vac, the gas started to drain right away. It was slow, because of the small height difference between front and back.

As Joe said, this got most all of the gas out of the tank and I could handle it with a floor jack easily. Once out of the car, I dumped another gallon of gas out of the corner vent.

A fun thread. Thanks for chiming in. steve


Car tank was about 6” above gas can. Took the can to front of car.



Connected the pump hose to a 5’ piece to get to cans in front of the car.



MAKE SURE TO USE THE PRESSURE SIDE OF THE SHOP VAC!!!!! Otherwise you will be sucking fuel fumes into the vac. It took just seconds to get enough pressure into the tank to push fuel through the hose to the can.



Good thing I am retired with time to spare. Slow flow, for sure. I did have a shorter 2.5 gal can, about half as high. That sped things up a lot.



Here is why you don’t want any ignition sources in the work area. Somebody before me added an extra fuel filter, and it decided to crack and leak today. So slid a tray beneath to catch the gas.



Shorter can speeds up fuel flow.



The flaky fuel vapor system in my car, a 72 Cutlass convertible. Has 3 tank vents going into it, and one vent line that goes to canister.



The tank venting art work is behind the rear seat.



Picture of the tank. That mid point tank baffle seemed to stop me from trying to siphon the tank.



Fuel schematic for my car. I don’t have a fuel return line. One 3/8” center vent, and two 5/16” upper corner vents.