Mercedes: transmission, vacuum leak, vacuum lines

Question
92 300td. Reverse is ok. No forward movement unless you give the car a nudge. Shifts ok when you get the car moving forward. I've had alot of trouble with vacuum lines. Is this the place to look? Do you think it's a vacuum leak?

Answer
Gary,
What is the mileage on the transmission? By nudge what do you mean?... Having someone push the car to get it rolling?
If you move the selector into low will this allow the car to move un assisted?
A vacuum leak would usually cause the vehicle to shift at the wrong time or not at all.  
You may have a low reverse clutch that is slipping. Check the fluid for dark color and or burned smell.
Does the vehicle move easily in reverse?
Rob