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We have had several reports of
this problem. Reports of this situation apply to the full
range of vehicle manufacturers.
The problem results from the
controlled filler necks mandated on all vehicles including
light trucks, SUVs, and cars. In order to meet
anti-pollution guidelines, control gasoline fumes and
internal overflows, there are EPA mandated filler neck
specifications. These specifications make filler necks more
restrictive than they were in the "old days".
Restrictive flow through the
filler necks puts limits on the rate of flow.
Consider gasoline pumps: These
devices have automatic safety shut-off valves in the handles
to prevent overflow when the vehicle's tank is full and
prevent uncontrolled flow if the pump's handle were to be
locked in the "on" position and fall out of the filler neck.
These situations combine to
create a delicate balance between the flow pressure of the
gasoline, the speed gasoline can flow through the vehicle's
neck, and the sensitivity of the automatic shut-off valve in
the pump handle.
When the situation described
in the above question occurs, it indicates that the rate of
gasoline flow from the pump exceeded what was allowed by
shape and specification of the vehicle's filler neck.
A solution is to "hand-meter"
the pump handle to try to ensure that gasoline does not flow
too quickly for your vehicle's filler neck.
Another solution is to locate
a gas station where the pumps are set to flow somewhat
slower when the handle is turned on. This will may mean the
gasoline will flow down the filler neck faster than the pump
supplies gasoline. This situation will prevent the auto
shut-off valve from being triggered.
Also, a problem may arise
following routine maintenance of gasoline pumps. Sometimes
the mechanism is reset to be more sensitive and shut off
with less back pressure than it had before. Sometimes
following maintenance, gasoline will flow somewhat faster
than it had previously. In this case the same vehicle that
received a one-stop fill previously, may now start
activating the auto shut-off mechanism. To resolve this,
find a new pump and / or gas station that works -- until it
doesn't. |