Community Forums

MikeGee · 04-09-2019, 04:19 PM

In chasing down some air leaks, I have a 3-way fitting on the front of my coach with compression fittings. 5/8" line going in to each connection and the bottom one is leaking. I replaced the brass sleeve and re-tightened . . . still leaking. I then replaced the nut and another new brass sleeve . . . still leaking. I noticed this connection did not have a ferrule/sleeve in the tube. Should it? Also, any other tricks to ensure a good tight connection with these compression fittings? I am pretty handy and mechanical and was surprised this seemingly easy task did not work. Any suggestions are welcome!

Mike

(I know some may recommend replacing with push to connect fittings. I did not pursue this as the other two connections are okay. Plus heading out with the RV tomorrow and could not source one locally very easily.)

twinboat · 04-09-2019, 04:41 PM

It should have a ferrule.

Take another one off and take a peak.

exrench · 04-09-2019, 05:09 PM

The issue is probably the 5/8 line that became deformed from vibration. The new sleeve is probably leaking between it and the tube. The solution is to replace the line. An easier route which I would try,is to get two wrenches and get crude with them. Make sure you use TWO wrenches.

garry1p · 04-09-2019, 05:10 PM

Over tighten is the biggest cause for leaks. I suggest.

Hand tighten then add one full turn if leaks add another quarter to half a turn until the leak stops. By doing this in iterations, you minimize the risk of over tightening. You can always tighten it more if you under tightened it, but once you over tighten, you have to get a new ferrule.

Garry

Mr_D · 04-09-2019, 05:17 PM

YES, the inner sleeve is required or it won't seal as you found.
I bought a 2014 CR-V that was " professionally" set up. I went to move a badly placed air fitting inside and there was no inner tube. Went through the whole system and found several more that were missing. Got new ones from Roadmaster (a 10 mile drive gor me) and redid the whole setup.

Dutch Star Don · 04-10-2019, 12:22 AM

I just did some airlines with compression fittings and they didn't use the sleeve inside the tubing, just the ferrule on the outside. You need to cut off the old material and then reconnect. If you don't have enough airline, you may want to replace the entire piece. If that's not practical, buy a short piece and a push on fitting coupler, so you can extend the hose length.

I carry push on couplers for all sizes of air hose on my coach. In an emergency, like something impacting an airline, I can repair it.

MikeGee · 04-10-2019, 04:49 AM

Thanks to all. Good information.

ScoobyDoo · 04-10-2019, 05:50 AM

Plastic air line compression fittings need 3 pieces; Nut on line first, then the ferrule on line, and a sleeve inside. The line needs to be cut square, and smooth. Sometimes the fitting can be damaged where the ferrule seals. No sealant on threads of the compression side.

ronaprhys · 04-10-2019, 06:00 AM

Another trick that you can try, if it doesn't fit and the line looks like it might've been deformed, is to trim the airline right behind the current fitting and the re-attach it. That way you don't have a damaged line causing a leak.

Also, new ferrules and sleeves may be in order. Most hardware stores sell those inexpensively.