Can someone tell me the best way to remove stale fuel from a 740 wagon fuel tank? Thanks

Did you ever figure this out?

The best way is to use the fuel pump in the tank!

If Bosch, this definitely works. If it has Regina (square coil), I am not sure, but I think it has the same connector.
Disconnect the rubber line feeding the high pressure pump. It is rubber, and held on with a clamp.

Put a coupler on the tube, and pump the fuel into a container by applying (or having a helper apply) 12v to fuse #11 inside the cabin. Keep the doors and windows closed so a spark doesn't cause a fire.

You can also disconnect the return line under the hood, but that is a lot more hassle in my eyes.

Years ago changing out main pump and filter. Disconnected the hose and after a fews minutes fuel started coming out via gravity. Had to add a section of hose and raise it above the level of the tank. You might give that a try. Definitely need to change your filter.
--
Post Back. That's whats makes this forum work.

I can't figure out how to respond to the posts I received....if this is the wrong way sorry. The gas is 4-5 years old. Can't siphon it out via the fuel filler. Really don't want to remove the tank. Not sure I understand how to get it out via the return line.

I’m talking about removing the entire sending unit from the tank and then putting a siphon hose into the big opening in the top of the tank. Not through the filler neck.
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

You could siphon it out into a container that’s sitting on the ground below the tank level. If you jack up the rear end of the car it would give you more elevation drop plus provide a deep area of fuel at the forward side of the tank. Once you’ve sucked out as much fuel as possible you can wipe out the remaining gunk with a rag if your hand is small enough to fit through the access opening.
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

I just had to do this on the V8 245 I'm building. It had gas that was easily more than 12 years old. I had to remove the tank unit so as to eliminate the in-tank pump and found the T.U. and inside of the tank rusty and filled with stinky gas (5 gallons). I used an aftermarket electric pump to empty my tank through the T.U. opening. Given that the 740 tank is plastic you may not have that problem.
In your situation I'd either use the inlet hose to the main pump and jump the push pump - or use the outlet of the main pump and jump both.
Next you're faced with what to do with the spoiled fuel. I was concerned and went around the corner to a local repair shop to inquire what they do. Julio told me he'd take it to add to his waste oil heater and that solved my environmental concerns. - Dave

I'm not following, what is the t.u. opening?

Sorry, 'cause I thought it was obvious since I had just mentioned Tank Unit and I'm sort of lazy. 4-5 years old is old but not real old--how does it smell? -- Dave

From the questions you have asked--and some facts that have been omitted I think you need to understand the system a bit better. Underneath the car the main high pressure fuel pump and filter reside in a carriage. Inside the tank the fuel pickup incorporates a second electric pump- of submersible type - that pushes the fuel to the main pump. So - my question is - does either of the electric pumps work? Ideally- if the "push Pump" works you can energize it by finding the wire that supplies power to it. I'm more familiar with the 240 series but there are folks on the BB who know the 740. If you bypass the car's electrical system and supply 12v. to the low pressure pump you should hear it hummm. That would be a good thing. At That point--with the car safely jacked up in the rear -- with jack stands under it and a catch can or drain pan handy you then disconnect the thick hose from the tank to the underneath fuel pump. If you are lucky gas may flow out by gravity -- or you can hold a rag over the filler pipe and blow a little compressed air (if you have it available) past the rag and that may get the flow going. But it may not flow past the pump in the tank -- and if you have determined it works you can apply 12v to it and literally pump the fuel out. If it does not work you may have to remove the "tank unit" - located on the tank facing the differential which opens a good sized hole into which you can insert a hose for the purpose of siphoning the fuel out. A paint store that sells kerosene should have an inexpensive siphon bulb and hose. -- Dave

How old of gas and about how much?
--
Post Back. That's whats makes this forum work.

4 or so years old, just under half tank

4-5 years old, just under half tank