Delayed Engine Shutdown Procedure; Sudden Loss Of Power - Komatsu 730E Operation & Maintenance Manual

OM3070
Operating Instructions
DELAYED ENGINE SHUTDOWN
PROCEDURE
Refer to Section 32, Operator Cab and Controls, for
identification of the various switches and indicator
lights.
1. Stop the truck. The truck must be away from
other traffic, on a level surface, and away from
overhead power lines or other obstructions.
2. Reduce the engine speed to low idle.
3. Place the selector switch in NEUTRAL.
4. Apply the parking brake switch. Ensure the
parking brake applied indicator light in the over-
head display panel is illuminated.
5. Move the top of the engine shutdown switch to
the ON (center) position. Then, firmly press the
switch to the MOMENTARY (upper) position.
Hold this position briefly to activate the idle
timer. The switch is spring-loaded and will
return to the ON position when released.
6. When the engine shutdown
timer has been activated,
the timer delay indicator light
in the overhead display
panel will illuminate to indi-
cate that the shutdown tim-
ing sequence has been
started. The engine will continue to idle for
approximately three minutes to allow the engine to
properly cool before turning off.
NOTE: The engine shutdown timer switch does not
turn off the 24VDC electric power.
7. Turn the key switch to the OFF position to allow
the engine to turn off when the timing sequence
is complete. When the engine stops after the
idle period, the hydraulic bleed-down timer will
be activated and the 24VDC electric circuits will
turn off.
The engine will only shut off if the key switch is in
the OFF position.
NOTE: To cancel the idle timer sequence, move the
timer delay shutdown switch to the OFF (lower)
position. If the key switch is in the OFF position, the
engine will stop. If the key switch is in the ON
position, the engine will continue to run.
8. With the key switch OFF and the engine
stopped, wait at least 90 seconds. Relieve the
steering circuit pressure by turning the steering
wheel back and forth several times. No front
wheel movement will occur when hydraulic
pressure is relieved.
9. Close and lock all windows, remove the key
from the key switch, and lock the cab to prevent
possible unauthorized truck operation. Dis-
mount the truck properly.

SUDDEN LOSS OF POWER

If the engine suddenly stops, there is enough hydrau-
lic pressure stored in the brake and steering accumu-
lators to allow the operation of the steering and brake
functions. However, this oil supply is limited so it is
important to stop the truck as quickly and safely as
possible after the loss of engine power.
If the brake supply pressure drops to a pre-deter-
mined level, the low brake pressure warning light will
illuminate and a buzzer will sound. If the brake pres-
sure continues to decrease, the auto-apply feature
will activate and the service brakes will apply auto-
matically to stop the truck.
1. Bring the truck to a safe stop as quickly as pos-
sible by using the foot pedal to apply the ser-
vice brakes. If possible, safely steer the truck to
the side of the road while braking.
Dynamic retarding will not be available!
DO NOT use the service brakes for continuous
retarding purposes.
2. As soon as the truck has stopped moving, shift
to NEUTRAL and apply the parking brake.
3. Slowly release the service brakes to check the
capacity of the parking brake. If the parking
brake can not hold the truck stationary, apply
the service brakes and hold them ON. DO NOT
turn the key switch OFF, and DO NOT release
the service brakes.
4. Notify maintenance personnel immediately.
5. If the truck is on level ground, or if the parking
brake can hold the truck stationary and the
truck is in a stable condition, it is then OK to turn
the key switch OFF.
6. If safe to do so, have maintenance personnel
place wheel chocks or other mechanisms in
front or behind the wheels to reduce the risk of
the truck rolling.
7. If traffic is heavy near the disabled machine,
mark the truck with warning flags during day-
light hours or use flares at night. Adhere to local
regulations.
Operation - Section 30
Page 30-13