MP24.9722
09JUL09
SECTION I
625/625S SERIES LEVELING SYSTEMS
COMPONENT SELECTION
System Controls, Hoses and Harnesses. Components such as control systems used for after market installations on
motor homes are predetermined by HWH once the type of vehicle and jacks are determined. There are generic hose kits
and harnesses for class C and class A vehicles. The control systems and power unit / control box assemblies are determined
by the type of chassis and the jacks used with the installation. O.E.M. or specialty installers should contact HWH for specific
control system, power unit / control box assemblies, hose and harness information. There are different size pump / motor /
tank assemblies available if mounting space is limited. For class C vehicles, the control box assembly can be removed and
mounted in a remote location. The harness allows the control box to be moved about 3 feet from the power unit assembly.
The following dimensions show how much space is needed to mount a standard power unit assembly for class C and class A
style vehicles.
Standard Class C Power Unit / Control Assembly
Side View
Top View
12.0"
12.0"
21.5"
Standard Class A Power Unit / Control Assembly
Top View
Side View
13.1"
22.6"
9.3"
Figure 5
Figure 6
The standard class C style power unit / control assembly is typically used with systems that incorporate 6,000# capacity jacks
and smaller. The standard class A style power unit / control assembly is typically used with systems that incorporate 6,000#
jacks and larger. Examples: The class C power unit would be used with a system that has four 6,000# jacks or a system with
two 4,000# and two 6,000# jacks. The class A power unit would be used with a system that has two 6,000# and two 9,000#
jacks. If the above dimensions do not allow the installation of the power unit / control assembly, contact HWH
Corporation for other options. Remember, the control box can be moved from the class C style power unit /
control assembly.
Air Suspension Air Dump System.
If the vehicle is equipped with an air suspension, an air bag air dump system is
needed. Some vehicles will be equipped with a pilot air dump system. Most likely, if a pilot air dump system is used, there
will be a dump switch or button supplied by the chassis manufacturer. If the chassis has no air dump system, an HWH air
dump system will have to be used. This will have electrically controlled solenoid valves, a different touch panel, different
control box and necessary harnesses. Contact HWH with specific chassis information to obtain the proper air dump kit.
Due to variations in chassis’s, vehicle construction and vehicle equipment, typical systems, mounting brackets and
components offered by HWH may not fit every application, even when a specific application is listed. It is the installers
responsibility to address mounting requirements and issues before starting the installation. When variations are
encountered that require custom brackets or components, or typical mounting locations are not
available, contact HWH Corporation for assistance.
