In a well-run fleet, special attention should be paid to the
proper maintenance and storage of new vehicles. Extra care and attention to detail
should be taken to make sure vehicles that have spent longer times in inventory
are put into service with no product issues. These issues could be stall/no start
due to improper battery maintenance or vehicle vibration due to tire flat spotting.
The list below will assist in keeping the vehicle inventory protected and ready
for customer delivery.
Maintain battery charge on vehicles in inventory. At vehicle
delivery, test/charge the battery backup (topped off for 20 minutes or less) to
make up for any loss of charge that occurred during the vehicle transit time from
the assembly plant to the department.
Every 30 days in dealer inventory, test/charge the battery. This
step will allow the battery state of charge to be maintained, which will maximize
overall battery life. Vehicle batteries that are in inventory for extended amounts
of time without being maintained/ charged will see a significant overall reduction
in the battery’s service life. Just prior to putting the vehicle in service,
test/charge the battery one last time.
All tires, no matter the manufacturer, are susceptible to flat
spotting if the vehicle sits on the lot prior to delivery and is not moved or
driven for an extended period of time. Flat spots on the tires can cause vibration
Vibration issues for flat spotting can develop between 30
and 45 days, depending on the tire design, parking surface, and weather conditions.
These usually will be gone after allowing the tires to heat up after a few minutes
of driving at highway speeds on smooth surface roads.
Vibration issues that develop from allowing the vehicle to sit
without being moved/driven for between 45 and 90 days usually will be gone after
allowing the tires to heat up after 10 minutes of driving at highway speeds on smooth
To minimize flat spotting, tires should be inflated to 44 psi
for longer term storage in inventory. While having higher tire pressures during
storage has not been proven to eliminate this concern, under inflation has been
shown to contribute to its severity, so higher pressure is preferred to lower
On the average, tires lose 1 psi every 30 days. Additionally, there is a
1 psi loss in pressure for each 10°F drop in air temperature. For example, a tire
with 44psi at 60°F would have 35psi after 6 months in inventory at 30°F air
Vehicles should be moved every 30 days. If vehicles are allowed
to sit more than 30 days at a time, more noticeable tire vibrations may be noted.
Vibration issues that develop from allowing the vehicle to sit without being moved/driven
for more than 90 days may become permanent and would require tire replacement to
When put into service, the tire pressures must be reset to the
values on the Tire Pressure Placard for the proper ride, handling and fuel
Tire Pressure Monitoring System
The TPMS is learned at the assembly plant and should not need
to be re-learned for delivery unless wheels are replaced or rotated. Vehicles that
have been in dealer inventory for extended amounts of time may have a TPMS light
on indicating proper tire pressure is required. Properly adjusting all tire air
pressures to the recommended levels and driving the vehicle will turn the light
Extended storage may increase the opportunity for brake noise
issues. Vehicle braking systems tend to be self-cleaning while vehicles are in use,
preventing any build-up of corrosion on the brake rotor surfaces. It is a good
practice if a vehicle needs to be moved (such as to access other vehicles) to drive
it once around the block and apply the brakes several times. This practice will
not only eliminate the opportunity for rust to build up on the rotors, but may help
to minimize flat spotting of tires. Important:
Vehicles should be moved and brakes applied every 30 days in order for
this practice to remain effective.
At times, more extensive corrosion can cause pulsation due to
thickness variation. This usually happens when the vehicle is parked for long periods
of time in humid conditions and the braking surface area under the pads corrode
at a different rate compared to the rest of the braking surface area. Cleaning up
of braking surfaces (burnishing) can be accomplished by 10 to 15 moderate stops
from 35 to 40 mph with cooling time between stops.
Windshields and Wiper Blades
Vehicle windshield wipers are exposed to weathering elements
as soon as a vehicle is produced. During extended storage, the wiper blades may
not function well due to many factors: 1) dirt/debris/dried soap stuck on the blade
surface; 2) oxidation of the rubber blade; and 3) the rubber blade may take a
“permanent set” from non-use.
It is recommended that the wiper blades be cleaned with a
lint-free cloth or paper towel soaked with windshield washer fluid or a mild
detergent. You should see significant amounts of dirt being removed on the cloth.
Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road
grime, sap and a buildup of car wash/wax treatments may additionally cause wiper
Do not operate the wipers if the vehicle is extremely dirty
with gritty or sandy materials, twigs/sticks in the cowl area. This type of debris
dragged by the force of the wipers while dry may cause glass scratching.
The interior surfaces of the window glass may appear hazy
(due to surface deposits) after a vehicle has sat in a “closed-up” condition for
an extended period of time. It is suggested that window washing during the pre-delivery
inspection be performed with plain water. Washing by this method increases the amount
of time that the windows will stay clean, as cleaners generally leave a film
that accelerates the deposition of new dirt.
As vehicles age while in inventory, the potential for
fueling issues increases. Gasoline powered vehicles should not encounter any fuel related
issues while being stored for up to one year. Vehicles should have fresh fuel
added as needed or if in stock for over one year.
Do not allow vehicles to run out of fuel during idle
conditions. Allowing a vehicle to run out of fuel while idling may cause damage
to the fuel pump.
The Oil Life Monitor in new GM
vehicles will count down as vehicles
are started, moved and run for the purpose of battery charging. If vehicles
remain in stock for longer periods, steps should be taken. When the vehicle was
assembled, the oil life monitor begins counting down the useful life of the
If the Oil Life percentage indicates below 90 percent of the
oil life left before vehicle delivery and the vehicle is older than seven
months, it is advised that the oil be changed before putting it in service. If
the Oil Life Monitor indicates above 90 percent or the vehicle build date is within
six months or newer, the vehicle may be put into service without additional
action. If a vehicle remains in stock for one year or greater, you should
change the vehicle engine oil.