SMI Air Force One Brake System Air Line Connection in Coach Recommendation

Updated 08/04/2025 | Published 11/04/2015

Question:

I have a 1999 American Eagle 40EVS on a Spartan chassis with air brakes. Do you have an installation video or picture to clearly shows which air lines to splice in to? Ive completed the installation kit on my 2000 Silverado tow vehicle and everything worked perfect. I just want to ensure I have the correct lines identified to complete the coach installation. Thanks for your help.

asked by: Tony G

Expert Reply:

In the install instructions for the SMI Air Force One system part # SM99243 that you referenced the correct line to use for the Spartan Chassis is pointed out. I attached that picture.

The line to use is the coach's supply air hose. This line goes from the service relay valve to the braking air tank. It is 5/8 inch in outer diameter. This line is normally green and should not be confused with the treadle valve hose which is 3/8 inch in diameter.

expert reply by: Jameson C

click to enlarge

Tech

8/4/2025

What line is the metered line?

Jameson C.

8/4/2025

@Tech The green one pointed out in the picture above.

Tech

8/4/2025

@JamesonC no that's the 1/2" feed not the 5/8 metered line. Unless theres a photo I'm not seeing. I figured it out 8 hours ago and the units already back in the customers hands.

Jameson C.

8/4/2025

@Tech I'm glad you got it figured out. That's picture actually came from SMI so that's a little concerning they have the wrong line pointed out in their instructions. Which line was it?