I have a 1983 fj60 and I had a rusted out gas tank so I used the por 15 to stop the rusting. After that, the gas tank would leak out of the filler cap and only when extremely hot. It got worse and worse and it would do it just when warm out and so I replaced the charcoal canister. That did not fix the problem. Does anyone know if there is a valve or anything that can be replaced to fix this or am I just missing something with it. Any help would be appreciated.