dot tubing and fittings

[thomasinnv]

Most of the suspension air lines have been replaced with dot tubing and compression fittings, but there are still a few oem lines in place that I would like to replace, and hopefully eliminate some slow leaks in the process.

So, who would be a good supplier for 1/8" dot tubing and associated fittings?  I prefer to be able to order it online and just have it shipped to me.  There's really not anywhere near me that I can get anything that I am aware of.  I am in Bouse AZ.

[stevet903]

I've used both of these guys for various fittings and lines with good luck:

http://www.hoseandfittings.com/

http://www.ryderfleetproducts.com

Steve

[Joe Camper]

You are not suggesting replacing exzisting rubber air line with plastic are you?

If there is any movement at all that needs to take place between the ends it must remain rubber.

[thomasinnv]

You are not suggesting replacing exzisting rubber air line with plastic are you?

If there is any movement at all that needs to take place between the ends it must remain rubber.

I'm not doing anything with any of the brake lines, just the airbag lines.  Most of the hard lines have been replaced already but there are a few left here and there that I am going to replace, such as between the front leveling valve and the tee between the left and right side bags, and the line feeding the valve.  I found a couple of leaks at the adapter fittings and it just makes more sense to me to replace the hard lines with dot plastic rather than mess with trying to get them to stop leaking.  The dot plastic also makes for an easy roadside repair if the need arises.  (you never know when you might have collateral damage from road shrapnel or a blow out)

[Len Silva]

NAPA will have or can get what you need.

[thomasinnv]

I found the adapters/fittings on Grainger's website for around a buck a piece.  I ordered a hand full along with some extra sleeves.  I also ordered 50' of tubing, but not from grainger, they were really high.

[belfert]

I found the adapters/fittings on Grainger's website for around a buck a piece.  I ordered a hand full along with some extra sleeves.  I also ordered 50' of tubing, but not from grainger, they were really high.

Are you sure they have the DOT stamp for that price?

[luvrbus]

Only the push in type fitting are DOT stamped 

[Highway Yacht]

Only the push in type fitting are DOT stamped 

When I worked at a Fluid Power house, we sold Parker and Dayco-Eastman brass DOT compression fittings that were stamped D.O.T. on the cap. That was several years ago so maybe it has changed now. Most people also used an insert inside the nylon tubing along with the sleeve. 

[kyle4501]

If you are trying to avoid leaks, the push-in fittings should be avoided.
We use them on the machinery we build because it saves time in assembly - NOT because they are a superior product.
Push-in fittings depend on an O-ring to seal against the tube. Due to the design of the o-ring gland, when the o-ring dries out & cracks, it will separate & allow air to escape.
Also, If the tube end has a sharp edge, it can scratch the o-ring when the tube is pushed in. I've seen plenty that seals OK at first, but leaked horribly after a short time.

When we want a superior product, we use a fitting with a ferrule & nut. Takes longer, but no leaks (if you install them properly).

I've found a good selection of fittings at a small truck parts store. The Parker brass fittings I last bought have DOT stamped on the nut.
I haven't used any push-in fittings . . . . for the reasons I just mentioned.
YMMV

Good luck!
Kyle

[luvrbus]

I just checked a bag of 1/4 in fitting I bought from Ryder Fleet no DOT stamp on those I did notice a stamp on the fittings for the brake pods but it ii s for rubber.FWIW I did find out hose places are not allowed to sell a compression union for the DOT lines now.


good luck

[belfert]

I bought an ordinary brass compression fitting at the hardware store for the connection to my air ride seat.  I had the seat out this summer and it leaked pretty bad when assembled.  It turned out to be missing the insert inside the tubing, but I didn't realize that until after I bought another fitting from C&J Bus Repair.  I didn't check if the new fitting was DOT approved as I figured that C&J would sell me the right thing.

[Highway Yacht]

I agree that compression is far superior to Push-To-Connect fittings as long as the installer doesn't over OR under tighten them. The only Push-To-Connect fittings I would use would be the Legris Brand and then it would only be used with Poly tubing and not Nylon tubing. Only trouble is I am not sure if Legris (French Company) even makes DOT fittings and the Poly tubing has a much lower PSI rating than Nylon.

[thomasinnv]

they are not a push in type, they are the compression type with the insert.  The product description says this: "For Use With SAE J844 Type A or B nylon tubing, Standards Exceeds DOT Pressure Requirements for air brake systems."  I would not use the simple push in type connectors, I have always been leary of them.  I just don't trust them.

[Highway Yacht]

they are not a push in type, they are the compression type with the insert.  The product description says this: "For Use With SAE J844 Type A or B nylon tubing, Standards Exceeds DOT Pressure Requirements for air brake systems."  I would not use the simple push in type connectors, I have always been leary of them.  I just don't trust them.

Both the "A" & "B" nylon tubing is Air Brake tubing and is DOT Approved. The "B" nylon is a re-enforced tubing and usually does NOT require inserts since the wall thickness is thicker. I think most people just use the "A" tubing with inserts since it works just as well and is a little cheaper.