WHAT SIZE ARE THE AIR LINES ON AN M939 series?

[VULCANGUNNER]

What size are they?
The truck ain't here so I can't measure it.

DOT plastic tubing but what size?

What is the NPT thread size on the 90-deg outlet fitting on the bottom of the air dryer?

This info is not written in any TM or website on this planet.

Help a brother out. Thanks.

 

[Suprman]

Alot of it is 3/8 synflex like the air drain lines but not all. If you are talking about replacing lines that branch off and go to the brakes it is special line I believe.

 

[VULCANGUNNER]

Alot of it is 3/8 synflex like the air drain lines but not all. If you are talking about replacing lines that branch off and go to the brakes it is special line I believe.

I have been told both 3/8" & 1/2". Thank you for your input.