Welcome, my name is XXXXX XXXXX I will do my best to help you with your issue.
Where is it coming un-done? at the back of the machine?
Hi - yes, and you know if push a little too hard on the machine side if comes off the wall side.
You can try making a few slits in the female connection in the same direction as the connection. This will allow the fitting to compress more
Also if you don't have a clamp that has a hex end to tighten you might want to swao that out too. You can get it a lot tighter with a hex
I tried the slit thing...and opened up that up, but the fit was still loose. Good point on the hex nut.
On other thing you might try
If you have room behind the machine I'd try 2 4" elbows with an aluminum flex in between. This will give you more room to work and get the connections real tight then push the machine back into place. If you're using what I think you are you probably have very little wiggle room
Ok, we'll give that a try...thanks!