[rheavn]

Richard Entrekin & myself worked together on the project of diagramming the rear suspension air lines & supply tanks in an effort to understand how the tag axle is tied in to the system. The biggest hurdle was proving that the tag air bag supply tank was not one tank as it appears from the outside, but two tanks that are divided on the inside. While many manufacturers control the tag air bags with a tag axle 6-pack, Newell chose to tie the tag air bags to the corresponding drive air bags on the same side. You'll notice on each side there are two solenoid valves. They are used to isolate the tag axle air bags when the tag override switch is used to either add or exhaust air from the tag air bags.

Diagram Legend:
Orange air lines are 120 psi supply lines
Green air lines connect the height control valve "out" to the 6-pack HCV fitting.
Blue air lines are air bag pressure controlled through the 6-pack

Richard & I hope this diagram is helpful to anyone who is trying to understand their system.