How long would it take to replace an overflow hose - Mercedes-Benz part number 166-500-15-91?

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your GLE63S AMG. Replacing the overflow hose or bleed line is generally straightforward, even with a coolant flush and refill. The 3.6-hour estimate you're getting seems high for just that job unless there's additional work involved, like accessing hard-to-reach areas or removing other components. The dealership may be quoting more time due to these factors or for diagnostic fees. I would recommend getting a second opinion at a trusted repair shop. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!