Stop a leak on your gas tank. Brakes...

[Dug]

Seal-All Adhesive & Sealant
A strong hold on brake fluid



Like other adhesives, this one can be used on metals, glass, wood and leather, but it is the only household product I have ever used that will withstand constant exposure to gasoline and/or brake fluid (DOT3 and DOT4). J-B-WELD will work in some cases, but you have to thoroughly clean and dry the surface or it will fail. Seal-All will seal a leak in a master-cylinder-reservoir (non-pressure side) even if you apply it over brake fluid that has already wept out onto the surface. I have also used it to seal an old Coleman fuel tank, and also a weeping fuel fitting on the bottom of a gasoline tank on my bike. This stuff is not what I would consider a toolbox item, but  this is one of the items I like to keep in the "just-in-case" bag.