I recently completed the plumbing for my on board air system using 1/2" OD copper tubing and compression fittings. I have leak-checked the system and am not happy with the frog’s breath (very fine bubbles) I see emanating from the compression fittings. The compression fittings are as tight as I can make them and there are a total of twelve of them in the system … and they all do this. The system holds pressure for about a day … steadily declining, of course. I had expected pressure loss, as most pneumatic systems leak, somewhere. This is, however, beyond what I consider acceptable.
I am contemplating removing the copper hard line and compression fittings and replacing them with 1/2" nylon tubing and push connectors from HB, but I wanted to know if anyone’s using these extensively and, if so, how well they hold pressure (i.e. how badly they leak at the connection points – presuming a perfect 90 degree cut, of course). Heat and pressure ratings would also be useful, as my front air manifold is in the engine compartment.
I’m having zero issues, by the way, at my 1/4" and 1/2" NPT connections; those are all rock solid…