Hi Vanagon Types;

Once again I am hoping the combined wisdom of this group might help me assess an issue with my cooling system.  I was checking over the system to get ready for cold weather, and in checking the coolant level, which was fine, I saw something I have not seen before.  The coolant looked dirty and there were tiny black bits or flakes floating at the top. When I put my finger in the tank it does not come up coated as with oil, it is just wet.  The black bits are solid and feel like bits of rubber.  I am guessing a hose is breaking down.  There is no leak, the engine temp is normal and I am not losing coolant.  I am also not losing oil.

Quick background, I swapped the engine 6 years ago for a GoWesty 2.3 and at that time replaced all the hoses including installing steel pipes on the two lines to the radiator. I do not recall doing the heater hoses.  A visual inspection of the hoses shows nothing, they look fine on the outside.

If it is a hose, how do I find it?  Alternatively, do I just flush the system and run it until something obvious leaks, or am I risking plugging my radiator with debris, or maybe worse?

Thanks in advance for any suggestions.

Dave B
Boise