M813 brake line size

[deuceman51]

I need to get some brake line this week at NAPA and I don't have my M813 in front of me. Does anybody know what size the brake line is that goes from the airpack to the tee on the frame? I think it's 3/8, but I can't remember 100%. Thanks.

 

[rumplecat]

I will see mine tomorrow, if no one responds shoot me a PM.

 

[Autocar]

I don't know what size that specific line is, but the rest of the truck is all 3/8 copper. If you are getting new fittings, make sure that they are air brake fittings. The air fittings have to be DOT approved and they are a different size than standard auto parts/hardware store fittings. The threads are the same, but the thread diameter is about .020 smaller on the DOT(Bendix Westinghouse, etc.) fittings and they have an extended nose to prevent vibration cracking. The hardware nuts screw onto DOT fittings because the thread pitch is the same, but they are very loose fitting due to the diameter issue. DO NOT MIX AND MATCH!

 

[doghead]

I think he was talking about the brake fluid line, not the air line.

 

[Autocar]

Oh.

 

[deuceman51]

Yup, I needed the brake line size.