So I just bought this car a few weeks go, mint condition but did notice a small coolant leak in a hose right at the top of the engine. It had been patched but looked like it needed some work. Anyway I checked under the car today out of curiosity after flicking a rather large rock up under the car a few nights ago and there is a much faster coolant leak... I think... could be washer fluid but I don't think it is. Anyway It is leaking out and all over the alternator. I found a damp spot near a the top that looks like it is coming from where a hose goes into ... something, my car knowledge isnt that great. Anyway I figure I would try putting in radiator sealant which would hopefully repair any gasket leaks which has worked for me in the past. But I don't no where to put it. There is no cap on the radiator... And I know not to put it into the coolant reservoir... what should I do?

Thanks