01 SIENNA_U (L/O0008)
2282001 MY SIENNA (OM45406U)
Brake system
The tandem master cylinder brake system
is a hydraulic system with two separate
sub−systems. If either sub−system should
fail, the other will still work. However, the
pedal will be harder to press, and your
stopping distance will be longer. Also, the
brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a
single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses engine vacuum to
power−assist the brakes. If the engine
should quit while you are driving, you can
bring the vehicle to a stop with normal
pedal pressure. There is enough reserved
vacuum for one or two stops—but no
more!
CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your reserved vacu-
um.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard, much harder than nor-
mal. And your braking distance will
be longer.
ANTI−LOCK BRAKE SYSTEM (with
“ABS” warning light)
The anti−lock brake system is designed
to help prevent lock−up of the wheels
during a sudden braking or braking on
slippery road surfaces. This assists in
providing directional stability and steer-
ing performance of the vehicle under
these circumstances.
Effective way to press the ABS brake
pedal: When the anti−lock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the anti−lock
brake system work for you, just hold the
brake pedal down more firmly. Do not
pump the brake in a panic stop. This
will result in reduced braking performan-
ce.
The anti−lock brake system becomes op-
erative after the vehicle has accelerated
to a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerates to a speed below
approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery
road surfaces such as on the manhole
cover, the steel plate under the construc-
tion, joints in the bridge, etc. on a rainy
day tends to activate the anti−lock brake
system.
You may hear a click or motor sound in
the engine compartment for a few seconds
when the engine is started or just after
the vehicle is started. This means that the
anti−lock brake system is in the self−
check mode, and does not indicate a mal-
function.
ProCarManuals.com
01 SIENNA_U (L/O0008)
2472001 MY SIENNA (OM45406U)
Avoid long engine idling. If you have
a long wait and you are not in traffic,
it is better to turn off the engine and
start again later.
Avoid engine lugging or over−rev-
ving. Use a gear position suitable for
the road on which you are travelling.
Avoid continuous speeding up and
slowing down. Stop−and−go driving
wastes fuel.
Avoid unnecessary stopping and
braking. Maintain a steady pace. Try
to time the traffic signals so you only
need to stop as little as possible or
take advantage of through streets to
avoid traffic lights. Keep a proper dis-
tance from other vehicles to avoid sud-
den braking. This will also reduce wear
on your brakes.
Avoid heavy traffic or traffic jams
whenever possible.
Do not rest your foot on the brake
pedal. This causes premature wear,
overheating and poor fuel economy.
Maintain a moderate speed on high-
ways. The faster you drive,the greater
the fuel consumption. By reducing your
speed, you will cut down on fuel con-
sumption.
Keep the front wheels in proper
alignment. Avoid hitting the curb and
slow down on rough roads. Improper
alignment not only causes faster tire
wear but also puts an extra load on
the engine, which, in turn, wastes fuel.
Keep the bottom of your vehicle free
from mud, etc. This not only lessens
weight but also helps prevent corro-
sion.
Keep your vehicle tuned−up and in
top shape. A dirty air cleaner, improp-
er valve clearance, dirty plugs, dirty oil
and grease,brakes not adjusted, etc. all
lower engine performance and contrib-
ute to poor fuel economy. For longer
life of all parts and lower operating
costs, keep all maintenance work on
schedule, and if you often drive under
severe conditions, see that your vehicle
receives more frequent maintenance.
(For scheduled maintenance informa-
tion, please refer to the “Scheduled
Maintenance Guide” or “Owner ’s Manu-
al Supplement”).
CAUTION
Never turn off the engine to coast
down hills. Your power steering and
brake booster will not function with-
out the engine running. Also, the
emission control system operates
properly only when the engine is run-
ning.
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