Black specks in Coolant Overflow Bottle

[Phillip W]

I happened to be adding windshield washer fluid today and decided to take a look in the coolant bottle to find black specks mixed in the cooant. WTF?? Car has about 75,000 miles, and last summer had the coolant flushed after having my thermostat housing blow a part on me. Im guessing the hoses are breaking down is the only thing I can think of although the outside of them look almost new. Any ideas and if it is the hoses, which ones do I need to replace??

 

[EddieS'04]

Hoses deteriate from the inside. In the old days 3yrs. Nowdays before 5yrs replace. Replace all of them on the coolant.