Vacuum element for fuel filler door melted
 

What would cause the vaccum element for fuel filler door on a 1986 mercedes 560sl to melt? I have been reading about the importance of vacuum for door locks, hesitation, etc. but no post talks about a melted vacuum element, WTH could do this?
See picture below.

Wow...maybe years of gasoline splashing onto it melted it?

vacuum element for fule filler door
 

jonathon, the gas is on other side of fender, how could it ever get to inside of fender?

A small amount could have seeped in over the years...the seal probably doesn't seal so well anymore after 20 years...

Battery acid - either not properly vented, or at one point and time, the battery exploded.