As I was changing the oil on my Mustang and checking all the fluid levels I glanced at the radiator fluid reservoir and noticed that it was low AND that there was a lot of grime and crap inside. I took it out and looked at it closer and it is pretty dirty in there along the inside walls. Is there a recommended way to clean it? Is it even necessary?

 

That is probably not a big problem. There is quite a bit of buildup in the radiator anyway, but it wouldn't hurt to clean it out.

The easiest way would be to use a wet/dry Shop Vac. You can stick it down in there and stink everything up. If you cannot get access to one, you can pull it off and clear it out. There are a set of screws you pull and then lift it up and spray it out.

 

if you plan to do what will just said i would also recomend doing a system flush just to make sure you get everything out of your system