Trying to fig out how to determin if its air blockage , head gasket, or water pump. I have been told those and also cap and thermastats but done did those. For starter never had problem until line from resevoir tank to radiator rubbed hole and started leaking never got above 210 the low coolant light come on I added fluid to get me to next exit and fixed leak now since then it loses fluid out tube on tank and yes top hose is hard all signs for head gaskets but radiator and bottom hose stays cool to touch now I wonder if its heads or not because should still circulate the same and all hoses should atleast be somewhat the same temp any help would be great