2008 Magnum R/T. Does anyone know what this component is and what is does? I have come from a 300C and can't remember seeing it before. I ask because it is not fully tightened; in fact it is quite loose. Should it be tight? Please click on thumbnail for full size image.

it's a pressure release for your air condiontioning i believe. it's just a cap, there is a valve under it.. kind of like a valve stem on a tire. whatever you do don't take it off and press it in lol.

That is an A/C line. Is the cap loose or is it loose at the bulkhead? Does your A/C blow cold? If it is depleated, you are looking at a new dryer and a refill.. $$$$$$

Thanks guys - that's very helpful info. It's just the black cap that is loose, it's fine at the bulkhead. Should I tighten the cap? A/C seems to be fine, though not as cold as my 02 Ranger!

Yeah, tighten the cap with your fingers, its just like a tire valve cap.

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If it hasn't got four wheel and makes a damned hell of a lot of noise, its of no concern to me.