I was searching for clues as to why I'm experiencing wheel bearing noise, a subject for another discussion, and I noticed a bunch of dried up crud on my left front CV boot. It appears that my strut has leaked some oil from the bottom, which in turn has attracted dust and turned to a greasy crud. There is a small plastic tube that penetrates the bottom of the strut (I assume this is the 4-C system adjustment?) and this appears to be the source of the leak. Do you think this strut is AFU? Do you think it would be covered under the CPO warranty?