• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

Replacing copper air lines in an 809 series

Ajax MD

Ajax MD

Well-known member
1,569
1,414
113
Location
Mayo, MD
A couple of simple questions:

  • How difficult is it to replace the hard air lines on an M813? I know that there are new, modern materials approved for highway use. Are they easier to work with than the copper lines and fittings?
  • Is this something that should be a preventative task? How often do the hard lines fail? Is the mode of failure typically "catastrophic" or is it more of a slow leak that gives warning?
With these big trucks, I'm all about safety but I'm also about not tearing stuff up needlessly.
 
Mullaney

Mullaney

Well-known member
Steel Soldiers Supporter
Supporting Vendor
7,716
19,766
113
Location
Charlotte NC
Ajax MD said:
A couple of simple questions:

  • How difficult is it to replace the hard air lines on an M813? I know that there are new, modern materials approved for highway use. Are they easier to work with than the copper lines and fittings?
  • Is this something that should be a preventative task? How often do the hard lines fail? Is the mode of failure typically "catastrophic" or is it more of a slow leak that gives warning?
With these big trucks, I'm all about safety but I'm also about not tearing stuff up needlessly.
Click to expand...
.
Vibration is the killer for the copper lines. That problem is exacerbated if there are loose supports for those copper lines. Where somebody removed a support and the tubing flops around and that sets up a failure.

I am not an expert, but if you use your house for an example: The copper plumbing is well supported. It keeps the tubing from bouncing around when you turn the water off and on. The house doesn't move, but the pipes can if they aren't secured. Same with the truck. My house is 40 years old since it was gutted and replumbed. The copper pipes in that situation are perfectly good...

There are DOT Approved nylon lines for truck air systems. Those plastic lines need to be anchored to the frame the same way as the copper. EVERYONE HAS AN OPINION. Mine is that if you carefully inspect the copper and don't see rub marks on it, chances are it will last longer than you.
 
Last edited:
BKubu

BKubu

Well-known member
Steel Soldiers Supporter
4,763
1,164
113
Location
Gaithersburg, MD
I once lent an M35A2 to a friend who wanted to towbar another M35A2 out of a local base after his purchase. Being younger and dumb(er), I agreed to let him use my truck and towbar. The recovery was a success. Upon pulling into my yard after he dropped off his truck, he hit the brakes (I was standing nearby). I noticed a stream of brake fluid shoot out from underneath the truck. Upon inspection, one of the brake lines had failed. Fortunately, it failed after he got back. I replaced the rusted line with nickel copper brake line purchased at Napa. I also inspected the rest of the brake lines and found they looked OK (from what I could tell).

I sold the towbar.
 
US6x4

US6x4

Well-known member
Steel Soldiers Supporter
1,234
2,246
113
Location
Wenatchee, WA
I just replaced my air horn copper line with a new line from Napa that I formed up and the original M813 copper tube was almost twice the wall thickness as the new line. I imagine you can order different wall thicknesses but it looks like the original is much beefier than a typical replacement.
 
Mullaney

Mullaney

Well-known member
Steel Soldiers Supporter
Supporting Vendor
7,716
19,766
113
Location
Charlotte NC
US6x4 said:
I just replaced my air horn copper line with a new line from Napa that I formed up and the original M813 copper tube was almost twice the wall thickness as the new line. I imagine you can order different wall thicknesses but it looks like the original is much beefier than a typical replacement.
Click to expand...
.
I did a quick search and apparently with (rigid) copper plumping pipe, there is a Schedule 40 and a Schedule 80.
All I know is that the different numbers relate to wall thickness. 80 is thicker. Outside dimensions are the same.

So I don't know enough to be really smart though.
I think we have one in our midst that can speak to copper pipe thickness.
Will PM him and hopefully get a "weigh in" on the question.
 
Last edited:
G744

G744

Well-known member
Steel Soldiers Supporter
1,715
3,845
113
Location
Hidden Valley, Az
One nice thing is the copper and Nylon can use (or reuse) the same fittings, as the OD is the same. The new fittings sold for use with plastic lines have a slightly different outside dimension, but either works.

One will have to buy new barrels for the job, as the old ones will be crimped on the used line.

I've swapped out some in hard to reach places, and just used the newer 'nuts' on the old brass. They thread right on.

Dennis
 
marchplumber

marchplumber

Well-known member
Steel Soldiers Supporter
3,801
2,828
113
Location
Peoria, Illinois
Rolled copper "soft copper" comes in different wall thicknesses. M is the thinnest. L is standard. K is for water service and H.D. applications. Original piping was probably type L copper. Replacement sounds like M. The O.D. are the same for all...............wall thickness is vastly different.

Hope that helps a bit.
 
M37M35

M37M35

Well-known member
Steel Soldiers Supporter
572
648
93
Location
East Central Oklahoma
Mullaney said:
.
Vibration is the killer for the copper lines. That problem is exacerbated if there are loose supports for those copper lines. Where somebody removed a support and the tubing flops around and that sets up a failure.

I am not an expert, but if you use your house for an example: The copper plumbing is well supported. It keeps the tubing from bouncing around when you turn the water off and on. The house doesn't move, but the pipes can if they aren't secured. Same with the truck. My house is 40 years old since it was gutted and replumbed. The copper pipes in that situation are perfectly good...

There are DOT Approved nylon lines for truck air systems. Those plastic lines need to be anchored to the frame the same way as the copper. EVERYONE HAS AN OPINION. Mine is that if you carefully inspect the copper and don't see rub marks on it, chances are it will last longer than you.
Click to expand...
My thoughts too.
I'm sticking with copper on my deuce.
 
Big Tom

Big Tom

Active member
212
114
43
Location
Millington md
Ajax MD said:
A couple of simple questions:

  • How difficult is it to replace the hard air lines on an M813? I know that there are new, modern materials approved for highway use. Are they easier to work with than the copper lines and fittings?
  • Is this something that should be a preventative task? How often do the hard lines fail? Is the mode of failure typically "catastrophic" or is it more of a slow leak that gives warning?
With these big trucks, I'm all about safety but I'm also about not tearing stuff up needlessly.
Click to expand...
Well my Cooper line just broke at the compressor outlet Friday on the way to graves mountian rally , was able to cut it clean and get it back together to get here , that line takes the biggest stress of all , don’t know if plastic line would take the heat there it gets hott. There is a splice by steering g box stoped at Lowe’s got 1/2” line and furrels replaced that section and when I get home going to do my other duece as a preventive measure

Big Tom
 
Jbulach

Jbulach

Well-known member
Steel Soldiers Supporter
2,661
2,194
113
Location
Sunman Indiana
They make a braided stainless line for the air compressor outlet. Believe it or not they are still some type of plastic on the inside. They handle the flex and vibration much better than coper.
Coper lines tend to brake at the flare or ferrule and no real good way of predicting or inspecting the connections that I know of.
 
MyothersanM1

MyothersanM1

19K M1 Armor Crewman
Steel Soldiers Supporter
1,958
427
68
Location
Culver City, CA
My M818 has been fully converted to dual circuit air brakes with s-cam rears and M939-series wedges on the front. Plumbing is mostly DOT push-to connect fittings and NT100 nylon air brake tubing. The existing fittings can be used with NT100 if you use the specific tube sleeves, nuts and inserts.
IMG_0334.JPGIMG_0341.JPGIMG_0347.JPG

I use SAE J1402A hose and fittings to the brake chambers.
DSC_0022.JPGPlumbing and Relay Valves (79).JPG

The air line from the air compressor to the air dryer is Teflon lined braided steel with AN fittings.
Plumbing and Relay Valves (68).JPGPlumbing and Relay Valves (69).JPG
 
Last edited:
Autocar

Autocar

Member
260
16
18
Location
California
If you replace any fittings, make sure they are DOT fittings. They are different than standard brass fittings. The nuts are longer to support the tube for vibration and the nut threads are different so that you can't interchange with standard brass fittings. Most likely have to go to a heavy truck parts supply house to get them.
 
You must log in or register to reply here.
110,897members
165,315threads
2,326,234posts
2,118online users
Top