AIR SUSPENSIONS AND HWH - HWH Corporation

3-7.3 Leveling lower mode schematic. The following schematic shows a tag axle system that used a tagaxle manifold with tag enable valves. Note that although the manifold has tag lower valves, these valvesare not used is a leveling lower procedure. The tag enable valves are open which connects the tag axle airbags to the drive axle air bags. The tag axle air bags are exhausted through the drive axle lower valves. Thetag lift exhaust valve is also on. This valve is tied electrically to the tag enable valves. This ensures the taglift mechanism is not trying to lift the tag axle when traveling or when in a leveling mode. Note that withthe air being exhausted from the right side air bags, the right side air bag pressure switch contacts are nowclosed. Although the contacts are shown closed, the pressure switch contacts would not close justbecause a lower function is done. The air pressure in the air bags must decrease to the pressureswitch setting for the contact to close.The above schematic could also represent a system without a tag axle. Just disregard the tag axle manifoldand all tag axle connections and information. If the system used a standard tag axle manifold or a standardstyle tag axle manifold with tag lift valves, the tag axle travel valves would not be on. The tag axle lowervalves would both be on to do a rear lower function.Page 29 – 22JUL09