The level in the overflow bottle has been dropping since I had the PHH replaced a couple months ago. Haven't noticed any leaks, but since I park on a dirt lot it's hard to notice. Figured I'd run a dye to see if any leaks show up... odd thing is the coolant level is consistently very high at the rad cap. So high it won't take any dye! I blew through the overflow hoses to make sure they were open... which they were. Why would I be dropping coolant level in the overflow bottle yet be maxed out at the radiator cap? Could something be clogging up in the rad system, or a sign that the HG is weakening? Blackstone shows no antifreeze in the oil. Original radiator. All major hoses less than 2 years old. Any ideas?