Got some news, some good, some questionable.

So I decided to fiddle with that rear door today. Lock button goes up/down as it it supposed to when I lock the car using the driver's door lock button. Door would not open from the outside. I didn't think it would open from the inside either, but today I climbed in the backseat and gave it another try. There was some pretty strong resistance on the inside door handle and as I pulled on it, I also pushed against the door and it popped open. So now that door will open from either the inside or outside easily whether the doors are locked or not. Even when the lock button on that door is down, the door is not locked. The button however does go up/down as it should when locking the car. So do you think this points to a vacuum or a linkage issue? The door panel has not been removed yet, but at least now I can do that since the door opens.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles