We recently had at our MB dealer perform a Service B, $1500+. 100 miles later, the power steering started squeaking, steering became difficult. At the same time we got a Coolant Level Low light on the dashboard. We were camping very remotely. So to help us getting home, I used the only oil I had on board: motor oil for the generator. Back to MB, they want now $700 to flush the lines and replace a hose. My position is that they did not check and replenish all liquids as I expected them based on the item checklist and as such the repair is a result of them not servicing the van correctly. Am I wrong?