Hi Maz49

If you are talking about the hose connection, which is on your Jayco to be permanently attached to a caravan park, water tap

Then just be aware that this thread, on most Jayco permanent inlet water connections, is an American thread
And that normal Australian water hose connection threads, will be either a BSP or MM thread, and will always leak

Below is a picture of the American thread, (which fits my Jayco Conquest), available from Bunnings, and perhaps available from other shops

Note that it says American Thread in the description, and that the Item Number (at Bunnings) is, 3111033

Hope that this info is useful to you, and others, with a Jayco motorhome or caravan 

If this is not the leaking connection, you are talking about, then a picture would be helpful