How Do I Attach the Air Supply Hose To The Air Tank of the Demco Coach Air Kit?

Updated 04/29/2026 | Published 04/27/2026

Products Featured in This Question

Coach Air Kit for Demco Air Force One Flat Tow Brake System

(78)

$383.35

Question:

HAVE THE NEW TANK AND NEED TO KNOW WHERE DO i PLUG THE SUPPLY LINE ON THE TANK?

asked by: GEORGE

Expert Reply:

Hi George,

For the Coach Air Kit for Demco Air Force One Breaking Systems part # SM99627, the supply air hose goes from the service relay valve to the braking air tank and is 5/8" in diameter. It connects to the silver regulator that sticks out from the side of the tank. I've included a photo that has the correct connection circled for the supply hose and linked a video showing its installation so you can see how our techs hooked it up.

Before you cut the line, make sure the supply hose is 5/8" in diameter, if you have a newer Freightliner Super C chassis it may have a 1/2" diameter supply hose. If the hose is not 5/8", you'll need to get a 1/2"x1/2"x1/4" tee from Demco or a local hardware store as the provided tee is for a 5/8" line.

What motorhome are you installing this kit on?

expert reply by: Claire H

Bill C.

4/29/2026

Was a fairly simple install, biggest issue was drilling holes in the frame for installation. Directions were very clear, for the installation on my 2001 Holiday Rambler Endeavor. Thanks for the clear installation instructions that showed multiple brands of motor homes, helped tremendously! Thanks again!

Claire H.

4/29/2026

@BillC I'm glad the installation went smoothly for you! What car are you flat towing with your Endeavor?

Archie D.

4/29/2026

Works great no problems. Good instructions easy to follow. I did want to be the one cutting air lines. My service garage installed on the M2 freightliner chassis. The garage is a four person big rig service garage. Looks like a factory job. Took two hours. Has experience with air brakes and the tools to make it easy.