Mercedes Benz repair: 1985 Mercedes TD wagon rear door, detali, mb2

Question
1985 Mercedes Wagon TDT: rear door is very heavy to lift &
seems the lift system is completely out. Over time, it began
losing the ability to stay up on it's own, but now it's VERY heavy
to lift & will not stay up. This happened over night (after we got
it back from a mechanic, actually). How would we go about
repairing it? Is it related to the vacume system?

Any help you can provide will be appreciated.
Thanks!

Answer
Answer:

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=123193&M=617%2E952&GA=722%2E120315&C...

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=123193&M=617%2E952&GA=722%2E120315&C...

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=123193&M=617%2E952&GA=722%2E120315&C...