Toro Greensmaster TriFlex 3320/3420 Service Manual page 23

The function of the fuel evaporative control system is to
collect and store evaporative emissions from the fuel
tank and engine. The evaporate control system used on
Greensmaster 3320 machines uses a carbon cannister
to collect these evaporative emissions. Fuel vapors
from the fuel tank are vented to the canister when the en-
gine is not running. Vapors from the canister are con-
sumed when the engine is running.
The fuel tank on Greensmaster 3320 machines uses a
non--vented fuel cap. To connect the tank to the evapo-
rative control system, a fuel vent valve is positioned in
the top of the tank that allows tank venting through the
carbon cannister.
NOTE: If there is restriction in the fresh air filter, the car-
bon cannister or the fuel vent valve, the fuel tank may
distort due to venting issues. If the fuel tank returns to it's
normal shape when the fuel cap is removed, restriction
in the evaporative control system is likely.
Components used in the evaporative control system on
Greensmaster 3320 machines changed at serial num-
ber 312000000. Figure 1 illustrates the components
used in the evaporative control system.
Greensmaster 3320
Machines With Serial Number Below 312000000
On machines with serial number below 312000000, the
carbon canister is mounted under the fuel tank mount
plate. One fitting at the engine intake manifold is used
to connect the evaporative system to the engine. These
machines use an inline check valve between the carbon
cannister and the engine intake manifold fitting.
Machines With Serial Number Above 312000000
On machines with serial number above 312000000, the
carbon canister is mounted between the hydraulic res-
ervoir and leak detector tank. The evaporative system
includes two (2) connections to the engine: one to the in-
take manifold and the second to the air cleaner base.
Venting hose assemblies include a check valve in two
(2) locations as shown in Figure 1.
NOTE: The check valves used on machines with serial
number above 312000000 are included as a component
of the hose assembly and are not available as a sepa-
rate part. To ensure proper operation of check valves, do
not attempt to remove them from the hose assembly. If
either of these hose assemblies are removed, make
sure that they are correctly installed to insure correct op-
eration of the evaporative control system.
Page 3 - - 5 Gasoline Engine