Finding Where to Connect Air Lines to Motorhome to Install SMI Air Force One

Published 10/10/2019

Question:

Installing the Air force one on a Monoco Knight 34foot Road master chassis 2003 model and trying to locate lines to cut into. There is a WABCO unit directly in front of the Drive Axle. One threaded hose and one slip fitted hose both are 5/8. I am looking for the spring brake valve and the only thing I can locate is next to the Allison transmission and it attaches to the Emergency brake on the transmission. It is the only thing that I can find that is mounted to the rear of the Axle like the instructions tell me. It has one 3/8 red line connected to it.

asked by: David R

Expert Reply:

When installing the SMI Air Force One Supplemental Braking System For Motor Homes with Air Brakes # SM99243 you will need to find the supply air line and the metered air line on the motorhome.

On the Monoco Knight 34foot Road master chassis 2003 model the larger 5/8 inch line is the supply air line, and the smaller 3/8 inch line below the supply air line is the metered air line. See attached picture to see them pointed out.

It sounds like what you found so far is not the service relay valve so you'd want to keep looking. I attached a picture of that it would normally look like.

expert reply by: Jameson C