XK120 Fuel Tank Removal

Hi all -
Filled my new (to me) XK120 up with petrol for the first time this weekend - right to the top - only to discover it has a very bad leak.
(this probably explains what I thought was very high fuel consumption on the short drives I’ve taken it on so far…)

I was able to siphon it empty before polluting the environment too much, however did not have time to properly investigate and locate the source of the leak. From initial inspection, it looks to be from the tank itself rather than any pipework as it was dripping (pouring, I should say) out from the shelf panel that holds the tank.

Question - how easy is it to remove the tank? I assume it drops out below the car, rather than through the boot (trunk). Anything I need to be aware of, or is this best left to the pros?

Assuming it is the tank itself, and not the filler pipe etc, I will get the tank professionally repaired.

Tips and tricks welcome - pls advise, even if the best tip is to get someone else to do it!


First remove the boot carpet, filler hose cover and plywood floors, then you can see the filler and vent hose connections and level sensor. The leak could be any one of those. If you filled right to the top, my first guess is a loose or missing hose clamp on the vent hose.

Failing all those possibilities, the tank comes out the bottom. Your exhaust may be in the way, they usually are. There is a supply pipe connection at the upper right corner so you will need a big BSF wrench, 1/2" as I recall but I may be wrong.
Then undo the nuts on the four hanger rods and down it comes.

I do everything myself so I always encourage people to try their skills. Ask questions, no detail is too trivial for this group.

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whew…glad no fire resulted. As Rob said, after carpet and board removal look for the filler connection…may be hard to tell now after evaporation…if that is it…easy. fix…the problem is how to know. Use extreme caution as gas fumes can be ignited easily by any spark…a power tool, a garage door opener, a refrigerator motor, plugging in an extension cord. Disconnect the car battery prior to work. There is a drain plug often difficult to remove. As Rob said for tank removal, it is time consuming but not hard, take photos along the way…for re-assembly. There are ground wires. The fuel sender at the top comes out. There will be rubber or felt pads, two of the tank rods are longer…note which bolt rod is from where. BTW…it is my own practice to never fill completely to the top…up to the fill hose connection…and when even close…no hard driving corners til at 3/4…maybe silly…but that top connection is always suspect in my mind…had an Alfa burn to ashes due to a leak there.

If the tank resembles Swiss Cheese, I suggest replacing it. If you’re not concerned about originality, aluminum tanks are available. The XK120 is rear end heavy so removing a few pounds from the back seems like a good idea to me.

Also, it is necessary to remove the drain plug at the bottom of the tank. There is a filter attached to the plug. The filter is made from a fine brass screen, soldered to the drain plug. I’ve found with stiff parts like this, used of a low torque impact wrench is helpful. The multiple blows from an impact wrench seems to loosen bolts that otherwise won’t come loose.

Thanks everyone - yes, a fire was my biggest concern as the fuel was pouring out right next to the hot exhaust pipes.
I will attempt to tackle this task over the weekend - looking first at the filler neck and other connections.
I did notice a bit of a petrol smell in the boot (trunk) prior to this, but I fear it may be the tank itself simply due to the quantity and rate at which it was leaking - much more substantial than what I expect would result from a loose hose clamp.
I will let you know how I get on…