Radiator Hose Replacement

Well, if your car overheats, you can loosen the radiator cap to the first stop.. but, it'll spew coolant everywhere even if you don't remove it fully.

The "air purging" you may be thinking of is the purge screw located right smack dab in the center of the top of the engine.. it's like a hex plug with hoses coming out of it.

Replacing the top hose is a simple thing to do, and you shouldn't lose much coolant in the process. Just replace the hose, refill the radiator til it's full, run it up to full operating temp with heat on high, then shut it off, let it cool a few minutes, then open up that purge screw thing until you see bubbles. If it's straight coolant, you probably don't have any or much air in the system.

As stated above, then you add coolant as needed to the "burping" point at the hex screw.