Fifth Wheels, General Information
Warning: Do not use any fifth wheel that fails to operate properly. Doing so may cause loss of vehicle control, possibly resulting in severe personal injury or death.
Air-Suspension Dump Valve
Warning: Never exhaust air from the suspension while driving. The suspension will not absorb road shocks, possibly damaging components, and vehicle handling may be compromised. This could result in loss of vehicle control, possibly resulting in severe personal injury or death.
The air-suspension dump valve may be used to adjust the vehicle height in order to aid with coupling to or uncoupling from a trailer. See Fig.. When the switch is set to DOWN, the air-suspension dump valve deflates the air springs to lower the rear of the vehicle. In the UP position, the automatic ride-control valves operate for normal driving.
Fig. 1, Air-Suspension Dump Valve
Notice: Do not operate the vehicle over uneven ground such as ramps, speed bumps, curbs, etc. with the air springs deflated. Doing this may lead to air bag separation from the piston, preventing the suspension air springs from re-inflating.
Fifth Wheel Lubrication
Warning: A standard fifth wheel plate must be kept lubricated to prevent binding between the tractor and trailer. A binding fifth wheel could cause erratic steering and loss of vehicle control, possibly resulting in personal injury or death.
The standard fifth wheel plate must be kept well lubricated with chassis grease to prevent friction and binding between the vehicle fifth wheel plate and the trailer.
For a low-lube fifth wheel plate, inspect the condition of the low-lube pads. There should be no damaged or missing pieces. Slight puckering at the outside edges is normal.
For lubrication instructions, see Safety Precautions of the Western Star Maintenance Manual.