brake booster LEXUS SC300 1999 Owners Manual

STARTING AND DRIVING
249
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 reserve 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 vacuum reserve.
 Even if the power assist is completely lost, the brakes will
still work. But you will have to push the pedal hard ± much
harder than normal. And your braking distance will be
longer.

DRIVING TIPS
271
Supplement/Maintenance Scheduleº.)
CAUTION
Never turn off the engine to coast down hills. Your power
steering and brake booster will not function without the
engine running. Also, the emission control system operates
properly only when the engine is running.

IN CASE OF AN EMERGENCY
279
JUMP STARTING PROCEDURE
1. If the booster battery is installed in another vehicle, make
sure the vehicles are not touching. Turn off all unnecessary
lights and accessories.
2. If required, remove all the vent plugs from the booster
battery.
Lay a cloth over the open vents on the booster battery.
(This helps reduce the explosion hazard, personal injuries and
burns.)
3. If the engine in the vehicle with the booster battery is not
running, start it and let it run for about 5 minutes. During
jump starting, run the engine at about 2000 rpm with the
accelerator pedal lightly depressed.
4. Connect the jumper cables in the exact order shown in the
illustration: positive terminal (º+º mark)±to±positive
terminal (º+º mark), and negative terminal (º±º
mark)±to±engine or body ground. Note that you first connect
the positive cable to the discharged battery and then to the
booster battery. Next, connect the negative cable to the
booster battery and then to a solid, stationary, unpainted
metallic point (e.g. SC400: brake booster vacuum pipe
bracket, SC300: cylin der head) away from the battery. Do not
connect it to or near any part that moves when the engine is
cranked.
CAUTION
When making the connections, to avoid serious injury, do not
lean over the battery or accidentally let the jumper cables or
clamps touch anything except the correct battery terminals or
the ground.

MAINTENANCE
313
Vehicle interior
Items listed below should be checked regularly, e.g. while
performing periodic services, cleaning the vehicle, etc.
Lights
Make sure the headlight, stop lights, tail lights, turn signal
lights, and other lights are working. Check headlight aim.
Service reminder indicators and warning buzzers
Check that all service reminder indicators and warning
buzzers function properly.
Steering wheel
Check that it has the specified freeplay. Be alert for changes
in steering condition, such as hard steering, excessive
freeplay or strange noise.
Seats
Check that all front seat controls such as seat adjusters,
seatback recliner, etc. operate smoothly. Check that the head
restraints move up and down smoothly and that the locks hold
securely in any latched position.
Seat belts
Check that the seat belt system s uch as buckles, retractors and
anchors operate properly and smoothly. Make sure the belt
webbing is not cut, frayed, worn or damaged. Accelerator pedal
Check
the pedal for smooth operation and uneven pedal ef fort
or catching.
Brake pedal
Check the pedal for smooth operation and the proper
clearance and freeplay. Check the brake booster function.
Brakes
At a safe place, check that the brakes do not pull to one side
when applied.
Parking brake
Check that the lever has the proper travel and that, on a safe
incline, your vehicle is held securely with only the parking
brake applied.
Automatic transmission ºParkº mechanism
On a safe incline, check that your vehicle is held securely with
the selector lever in ºPº position and all brakes released.