[shad9876]

I am installing an air suspension setup and am using 3/8 inch push-in style fittings.
The first one I hooked up and tested leaked(air was leaking from the area between the hose and the collar of the fitting, not where the fitting threads into the tank and not directly where the hose pushes in, but between the collar of the fitting and the fitting itself.). See the arrow in the picture.


I tried a second fitting and did the same.

Is there a specific way to insert the tube or does it need to be cut a certain way or prepped...or did I just happen to get two bad ones.

I am a bit nervous, because these are the same fittings that are on each of the air shocks and it would really suck if they ALL leaked!

[Chris Kemp]

I hate those fittings but I have to use them everyday. I hate quick disconnect fuel lines too but I have to use them everyday as well. The reason that manufactures came out with these kind of fittings is because they don't require any tools to assemble. Less labor on the assembly lines means more money in the owner's pocket. When you cut the line make sure that it is a square and clean cut. Do not use any tool that collapses the line when it cuts it ie. side cutters or scissors. I use a razor blade and make sure I get a square cut. If you still have trouble then go to the parts store and buy the old style that uses an insert, ferrule and a threaded cap. When installed correctly the new style fittings are safe. All of the semi trucks and trailers that are on the roads nowadays have them on the airlines, but I still don't like them.

Chris

[vwhammer]

I can tell you, with my experience with air suspensions, that those fittings generally never work.

I know I see them or something similar on semis all the time and they function for hundreds of thousands of miles.
But I have even purchased those very fittings thinking they might be better and no dice.

We had so many problems and were wasting so much time with push lock and compression fittings that myself and a friend I used to work on this stuff with eventually started having custom length braided lines made with crimp on fittings.

It really is the only way to go for a reliable leak free system.
It is a fair amount more expensive but in my opinion it is totally worth it.

Also, if you have a local hydraulic line shop that can make the lines, you should check them out and I bet you will find that it is not outrageously more expensive than the push lock stuff with plastic line.

If you must use the push lock style fittings make sure you cut them square and be sure there are no burs on the cut line that may damage the O-ring inside the fitting.
Then take extra care to get any bend as far away from the fitting as possible.

Any side loading of the line in the fitting will surely lead to a slow leak.

After that you will push the line in the fitting and it will stop against the O-ring.
Don't stop there as you have to make sure the line passes the oring and seats in the fitting.
if you do one rigth you will know what I mean.

Other than maybe using some type of vacuum grease on the line to try to help seal things up and lubricate during assembly there really is not much else you can do.

One last thing I might note is the fact that those plastic push lock fittings are probably the cheapest and most worthless fittings you can buy.

You might try to step up to the brass or steel pushlock fittings.
They are a little more but if you do all the things I mentioned they just might work.

[59 wagon man]

Invest In The Recommended Cutter. I've Been Using These Style Fittings For Years On Water Lines. If The Cut Isn't Good They Leak. I Think Even Harbor Freight Has The Tool Or Try Air Ride Technologies Or John Quest Fittings

[shad9876]

Great suggestions, I will try to make certain that the ends are cut well. I had previously been cutting them with wire cutters, which cause them to be more oval shaped than round and I also did not pay particular close attention to the cuts being squared.

I will check into the cutter or try to use a razor.
Do I want the same type that you use to cut metal tubing or is it different?

Also, once pushed in, can you get them back out? I need to remove and re-cut the other lines, if possible. I have a fuel line disconnet tool, but it doesnt look like it would work on these fittings.

[59 wagon man]

YES THEY ARE reusable. once you relieve the pressure you push the tubing all the way in then holding that little ring down pull out the tubing

[bluesman2333]

I have used tons of these fittings. I have noticed a BIG difference between the chinese knockoffs and John Guest products, which amazingly enough are American made.

I suspect that if those who are having trouble with this type of fitting cut the tubing square with a razor or utility knife like I did and use John Guest, you simply will not have any problems.

[bluesman2333]

Oh and the next step up in fittings for this plastic tube is the brass compression ones like Home Depot sells. Make absolutely sure you use the little ferrel on the inside of the tube otherwise it will leak.

[powerrodsmike]

I use those fittings all the time, and they don't leak IF I cut the end properly, I use a razor blade or really sharp utility knife, cut it square, and de burr the end with some 320 sandpaper...JUST remove the burr, DO NOT scuff the surface of the tube.

I also use some silicone grease, made by Dow-Corning..it is a valve lube for water valves, vacuum and pressure systems and is totally inert and is specifically for use with O-rings.

I have no leaks on the stuff I put together..

Using wire cutters is the surest way to create leakes, and destroy the seal on those fittings. Once they leak because you nicked the o-ring, they need to be replaced.


And yes the cheap ones suck.

Later, mikey

[matts37chev]

you also need to make sure the ring on the fitting is popping out after you insert the line
in your pic it looks like it is still pushed in like you are trying to remove the tubing

[PneuFlex]

Originally Posted by shad9876

I am installing an air suspension setup and am using 3/8 inch push-in style fittings.
The first one I hooked up and tested leaked(air was leaking from the area between the hose and the collar of the fitting, not where the fitting threads into the tank and not directly where the hose pushes in, but between the collar of the fitting and the fitting itself.). See the arrow in the picture.


I tried a second fitting and did the same.

Is there a specific way to insert the tube or does it need to be cut a certain way or prepped...or did I just happen to get two bad ones.

I am a bit nervous, because these are the same fittings that are on each of the air shocks and it would really suck if they ALL leaked!

I think it's the problem with quality. For ********* products,we never met such problems. Maybe the colla is too small. Pls link here for reference:

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