Can't budge the radiator connect/disconnect isolation valve on a 2005 JD 6615. This is p/n AL164553. How would I go about removing and replacing this "plastic" valve? When I try and turn it with a hex wrench, the plastic just warps as the wrench turns.
FYI I started the drain and refill process because my hydraulic oil was overheating and from what I read it was likely an air lock on the low temp circuit. So draining, refilling, bleeding seemed to be the first course of action. But now I can't do that.