Toro V-21SB Operator's Manual page 23

The grass bag can be used for an additional test to
check the Blade Brake Clutch mechanism.
1. Install the empty grass bag on the mower.
2. Start the engine.
3. Push the control bar (Fig. 17) down to the lowest
position.
4. Lift the control bar to the normal "blade engaged
position, about one inch below the handle. The
bag should begin to inflate which indicates the
blade is engaged and rotating.
5. Release control bar. If the bag does not
immediately deflate, it indicates the blade is still
rotating. Deterioration of the Blade Brake Clutch
mechanism may have set in, which could result
in an unsafe operating condition. Have mower
inspected by an Authorized TORO Service
Dealer.
EN–12