Transmission coolant line?
 

I had my mechanic check out my 98 ML320 prior to purchase and he said the only flaw he could find was a slight leak in the transmission coolant line, which was about a $200 repair. What exactly is this? Also, what is the service interval on transmission fluid changes in the ML320? I have about 73K on it. THanks.

There have been some problems with the trannsmission cooler line set from the transmission up to the cooller. The leak takes place at the pinch fitting which joins rubber hoses to steel pipes. It is a common leak. The price seems about right, couple hundred for parts and labor and topping off the transmission.
There is NO service interval on the transmission fluid, and I for one (about the only one maybe) recommend leaving the fluid original and do not replace it, per MB.

Gilly