Heating Help

Fuel oil filter gasket question

I have a fuel oil filter gasket that leaked.  The filter assembly was several years old and the gasket has a red dye marking on the side and was found to be slightly larger than the replacement gasket (that came with a brand new filter and also had a red marking on the side).   Do the gaskets having a red mark only come from the filter mfg? 

What probably happened.....

was the gasket wasnt seated properly, or the filter wasnt tightened properly, and leaked.  The gasket is bigger from swelling or mis-alignment.  When you say the filter assembly is several years old, i hope you dont mean the filter hasnt been changed for several years. But otherwise, everything should be fine, if properly installed

gasket question

Thank you.  The tune up was done 4 days before the leak.  The filter cartridge looks like it had been replaced by the tech, but the gasket--not sure and that is why i am asking about the red dye mark on the side. 

probably what happened

the filter pot was filled, then tightened after? As soon as oil hits that rubber, it expands. I use the bleeder. There is one on every filter. New gaskets, tighten it, then fill thru the bleeder. Much safer. Was there quite a leak? sounds like it