So i just got back to my jeep today and noticed my gas cap was open and over 3/4 of gas siphoned, I was positive my jeep had an anti siphon mechanism inside if they took gas they had to have broke it right?
CF Veteran
On the 96 it is just a spring loaded plate that is pushed open by the gas-filler nozzle. So putting a siphon in does not really damage it. Perhaps it is different on a 99. It's not really anti-siphon but is meant to slow/stop the flow of fuel in the event of an accident. However, getting a siphon into the stock XJ tank is a pain because of the tight angles of the fuel filler hoses that run from the filler port down to the tank. I have a small siphon tube, and after much screwing around, had to give up on it. I could get it about 3/4 of the way down there, and it would get so jammed up in the filler tubes I could barely get it out again. I ended up using the fuel pump relay jumper method to empty my tank into a container directly from the fuel pump instead.
Does it fill? Is the flapper still there? It's nice that they didn't take a drill to the underside of the tank.
Old fart with a wrench
There is something you can do to try to stop the siphoners. Take the fuel filler pipe off and drill 2 cross holes at the very end where the hose overlaps. Install and weld pins in those holes, grinding the welds flush. This forms a cross baffle that makes it harder to get a siphon hose into the tank, yet doesn't restrict the pipe when you fill it. This was done on my buddy's El Camino and worked perfectly.
Old fart with a wrench
Not if you remove it to the workbench. What are you smoking?
I blame working in florida heat lol. But it doesnt sound like a bad idea at all it seems the only locking gas cap you can get for these are junk
Seasoned Member
My dads old van kept getting gas stolen too. He made a birds nest ball out of stainless wire a bit bigger than tube diameter and shoved that in filler tube. Our tanks have that small flap so you would have to put it in from bottom of fill tube.