Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › Radiator overflow bottle getting really high › Radiator overflow bottle getting really high October 20, 2011 at 11:00 am #452804 bk7794Participant cap is genuine and brand new. It only does this sometimes so I am assuming that the cap is okay. Come to think of it, the heater was off all those times. So I wonder if its overfilled. Do you think?