Originally Posted by Old Fool
They have rubber seals in them, try lubing them once in a while with some silicone spray.
I don't know about him but what I am referring to and I think this is part of what he is talking about are these nipples.
Even with a quality coupler these parts from HF or the like are JUNK and leak from the get-go. As far as oiling them, not in my shop or anywhere that painting is being done.