Preventive Maintenance
26
17730-299
ULTIMAAX
®
for Fire and Rescue Vehicles
LEAKING VS. MISTING SHOCK VISUAL INSPECTION
FIGURE 6-29
The inspection must not be conducted after driving
in wet weather or a vehicle wash . Shocks need to be
free from water . Many shocks are often misdiagnosed
as failures . Misting is the process whereby very small
amounts of shock fluid evaporate at a high operating
temperature through the upper seal of the shock,
see Figure 6-29 . When the “mist” reaches the cooler
outside air, it condenses and forms a film on the out-
side of the shock body . Misting is perfectly normal
and necessary function of the shock . The fluid, which
evaporates through the seal area helps to lubricate
and prolong the life of the seal .
A shock that is truly leaking and needs to be replaced
will show signs of fluid leaking in streams from the
upper seal . These streams can easily be seen when
the shock is fully extended, underneath the main
body (dust cover) of the shock . Look for these potential problems when doing a visual inspection .
Inspect the shock absorbers fully extended . Replace as necessary .
NOTE
The ULTIMAAX suspension is equipped with a premium seal on the shock, however this seal will allow
for misting to appear on the shock body (misting is not a leak and is considered acceptable) .
If the shock is damaged, install new shock absorber and replace as detailed in the Component
Replacement Section of this publication .