2007 Mercedes-Benz CLS550 fuel system problems

2007 mercedes benz cls-550, fuel system leak, 24,272 miles, towed to dealer, dealer claimed that fuel sender cap was very loose, dealer replaced gasket for fuel sender. Fourteen days after, refilled car with gasoline, had a fuel leak again, drove to local repair shop, mechanic found fuel leaking from fuel sender housing the plastic plug used to mount pressure sensor for evap. System, needs replacement of fuel sender.

My husband and I purchased the 2007 cls550 about september 2015. We noticed when filling the vehicle with gas, we would have gas fumes in the vehicle specifically on the passenger side rear inside and outside. The fumes were light and would dissipate once the vehicle was driven to reduce the amount of gas in the tank to about three-quarters tank. Last week we filled the tank and the small is now stronger and has yet to dissipate although we have a quarter tank of gas remaining.