That's why the title of the checklist is ENGINE FUEL LEAK CHECKLIST, there's nothing much you can do about a leaking fuel tank.
If it's an engine leak and you can stop it by shutting the engine down and closing the spar valve at least you haven't lost much useable fuel.
However if it's a tank leak about all you could do is feed all engines from the leaking tank until it's almost empty and then switch to the good tank.
Regards,
BH.