'88 300CE Seatbelt Arm
 

I'm waiting for the service CD to arrive for our "new" baby and I was wondering if the seatbelt arm is vacuum or electric power.I have a vacuum leak on the passenger side somewhere.I replaced the rubber line at the tranny (was a guess)as well as the two lines at the fuel door.If it isn't the arm then it must be the door lock,right?The door has not locked or unlocked sometimes but most of the time it's fine.'Removing the door panel' directions would be most useful as I don't want to break anything:) .Thanks in advance.