brake rotor Lexus GS300 2006 Starting and Driving

STARTING AND DRIVING
431
Drum−in−disc type parking brake system
Your vehicle has a drum−in−disc type parking brake system.
This type of brake system needs bedding−down of the brake
shoes periodically or whenever the parking brake shoes
and/or drums are replaced.
Have your Lexus dealer perform the bedding−down.
Brake assist system
When you slam the brakes on, the brake assist system
judges as an emergency stop and provides more powerful
braking for a driver who cannot hold down the brake pedal
firmly.
When you slam the brakes on, more powerful braking will be
applied. At this time, you may hear a sound in the engine
compartment and feel the vibrations of the brake pedal. This
does not indicate a malfunction.
The brake assist system becomes operative 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).
The brake assist system may not work for about 60 seconds
after the engine is started.
For an explanation of this system’s warning light, see “ABS”
warning light on page 78 or 430.
BRAKE PAD WEAR LIMIT
INDICATORS
G31006
The brake pad wear limit indicators on your disc brakes
give a warning noise when the brake pads are worn to the
extent that replacement is required.
If you hear a squealing or scraping noise while driving, have
the brake pads checked and replaced by your Lexus dealer as
soon as possible. Expensive rotor damage can result if the
pads are not replaced when needed.
GS430 front brake only—
The high brake performance is achieved by proper wear of
brake pads and discs. As a result, the brake discs may wear
earlier than the ones on the conventional brake system.
When brake pads are replaced, brake disc thickness is
required to be measured.
It is dangerous to continue driving when brake pads and discs
have exceeded the wear limit.