Fuel Tank Cap Stuck

Hi all from Australia .
I’m trying to unlock the fuel cap , I have the correct key that goes in ok but it will not turn .
I have had it soaking in penetrating lubricant for some time as well as liberal doses up under the cap as best as I can manage , I suspect that the spring load tabs that lock in are rusted tight , I’ve tried shocking it loose as well but no luck .
The cap itself will not press down at the front at all which I always used to do when I had a Bol-D’or many eons ago to take the load off the mechanism when turning the key .
Any suggestions ??
The next thought I have had is turning the tank upside down into a container filled with kerosene so the whole cap is under ??

I had a similar problem in that the key was ok in the ignition but would not open fuel cap and toolbox. I took the key to a locksmith who checked the codes? and cut another key which worked perfectly. Apparently a little bit of wear on the key and locks can stop them working.

It’s not that as one , the key works perfectly in the ignition and toolbox and also there is absolutely no movement in the cap at all , zero .
Ill soak it in kero for a week or two and see how that pans out .

Ok - let us know if this fixes it.

I’ve had the issue before myself. Mine was due to being dry and corroded, so the tabs wouldn’t retract. If you take the fuel send off the bottom of the tank, you can just about see the cap with a torch. You might be able to soak them directly with penetrating oil or even get a tool on them help compress them. Hope it goes well!

Dear Groot430LS!

Only an idea but I’m sure you are aware of this:
If you turn the key, you directly turn the two bolts which locks the cap. Inside the cap there is a spring. If you close the cap you have to squeeze the spring inside the cap and the bolts will snap in the tank. If the bolts are very tight to the tank and also the lock is corroded, you will not be able to twist the key.
So press the cap down to the tank to lower the force of the spring and to break free the bolts (it they are also corroded to the tank).

That is the problem , there is zero movement in the cap , even when its working properly the cap should be pressed down before you turn the key to take take the load off the turning the key .
I have tried to shock it free as well but it wont budge .
I think the spring and the lock bars are all rusted up .
I’ll remove the tap and turn the tank upside down and partially fill it with my special penetrating mix and leave it for a week or 2 soaking .