1997 E300D TRANSMISSION ELECTRICAL PLUG

[rodm]

The plug for the transmission is leaking. It was changed in July 2013 after it had been leaking for some time. It has not leaked since then. A few days ago the vehicle began having shift problems while out on the road. At home upon parking the vehicle a LARGE puddle was observed under the car. It appears the plug is leaking again. Upon putting the car up on ramps and removing the plug about 1 pint of fluid drained out is that normal ? Can i spray contact cleaner on the pins or will that get into the transmission ?....any ideas on the premature failure of the plug?

THANKS ROD