Originally Posted by FunkMasta
Maybe isn't possible is not the correct phrasing... it is prohibitively difficult. Sometimes to flush the way that is normally done in the industry (using an external cooler line to tap into) requires special fittings that are difficult to get, or the fittings are difficult to get access to. Ideally we want the car in a state it can run. If you have to take half the engine bay apart to tap into a line, its far easier (cheaper for the customer) to drain and fill. No one wants to pay 3+ hours labour for a flush.