Good source for air coupling nuts and air lines

[dieck]

Hi All,

I've had my deuce for about a week and am working my way through all the systems. I've found several air leaks I would like to resolve. It looks like most are around the "coupling nuts" referenced in the attached image from the service manual. I will probably need to replace some air lines and coupling nuts. Is there a standard specification for these items for an M-35a-2? Should I be looking surplus or is there somewhere I can buy them new?

Also I would like to cap off a couple that are leaking. Is there a screw on cap I can use to terminate an unused air connection? The previous owner bent the copper tubing but the leaks are before that at the actual nuts.

http://www.steelsoldiers.com/member...okup-picture13408-air-lines-coupling-nuts.gif

I did try to search but couldn't find a thread that addressed this although I must assume it is a common problem.

Thank you!

Heath

 

[Westech]

Home depot, Menards, Ace , true value, local hardware store......ect ect ect

 

[dieck]

Home depot, Menards, Ace , true value, local hardware store......ect ect ect

Hmmm. I looked over the coupling nuts at the local HW store. The threads didn't fit. I wonder if the threads are just mangled. I assumed it was some gold plated military non-standard connector.

 

[73m819]

buy the WHOLE fitting,( fitting, compresson nut, compresson ferral,) and some tubing, a lot easier

 

[drgreg]

Don't ask for a coupling nut at the store, you will probably end up with a long nut (hex nut).
Ask for compression or flare fittings. If it is compression, follow 73m819's advice. If it is flare, you are going to need more help and special tools. I don't remember which kind it is.

 

[73m819]

it is compression, the mil uses the long nut, some of short nuts wont on the mil. fitting using the existing farrel. if you need a nut, you will need to replace the farrel as well. so might as well just start over

 

[Autocar]

You can't use auto parts/hardware store fittings. Air brake fittings are different and must be DOT approved. Also, air brake fittings have extended nose nuts to prevent vibration cracking. The reason your truck fittings are loose when you use standard fittings is because the threads are different. The thread pitch is the same, but the thread diameter is about .020 different and it is dangerous to mix and match along with not being legal to use(DOT approval). Most fittings are made by B-W(used to be Bendix-Westinghouse)and they are available from heavy duty truck supply houses. I got mine from Fleet Pride. They are also available on line if you look up "truckair brake fittings".

 

[renovate7]

What you have are a lot of copper lines and compression fittings, pretty standard stuff. I strongly warn you not to buy any of these fittings at Home Depot or Lowes. They carry the same brand, they will fit many of the places on your truck, and they are soft brass JUNK. Tightening up a compresson nut and you are likely to strip the threads, ask me how I know. I bought all my fittings at a NAPA. They are marked and manufactured by Eaton. Hold one next to a HD/Lowes fitting and there is a world of difference.

 

[m16ty]

It's more than likely not the nuts that are your problem. It's the ferrule that's under the nut. You can usually reuse the nut and just replace the ferrule and/or line.

If you're not worried about keeping everything stock, I like to go back with plastic DOT line when I replace them. It's cheaper and alot easier to deal with.

 

[73m819]

It's more than likely not the nuts that are your problem. It's the ferrule that's under the nut. You can usually reuse the nut and just replace the ferrule and/or line.

If you're not worried about keeping everything stock, I like to go back with plastic DOT line when I replace them. It's cheaper and a lot easier to deal with.[/QUOTE]
this also handles vibration better , just be sure to use the insert

 

[Autocar]

I checked the fittings this weekend. Both fittings have 9/16-24 threads. The standard fittings thread OD is .560" but the DOT fittings are .530" OD. This is why the existing DOT truck nuts won't thread onto the hardware store fittings and the hardware store fittings are extremely slopply on the DOT truck fittings. Use either DOT air brake brass fittings or like suggested above use DOT plastic lines and their matching fittings.

 

[m16ty]

Just a note- You can reuse the copper line nuts on the plastic DOT lines.

 

[jonesal]

I get all these fittings at my local NAPA. They are all in the Weatherhead/Eaton catalog under the brass air brake section. I've attached the catalog pages here for your convenience. The catalog numbers are the NAPA numbers.

View attachment Brass Air Brake Products.pdf

Allen
'70 M35A2
'55 M38A1

 

[renovate7]

Congratulations on buying quality fittings, seriously. The stuff at the big boxes is junk... Make sure if your running new copper lines that you leave some slack in them. I've found that most times after tightening a fitting once the ferrule is pressed into the line making it impossible to slide it off. If you need to redo something you end up cutting it off and using a new ferrule.