Brake Booster; Anti-Lock Brake System - Toyota Tacoma 1998 Operating Manual

Brake system
TANDEM MASTER CYLINDER
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
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 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.
144
BRAKE
"
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
automatically help prevent lock- up of the
wheels during sudden braking or braking
your
on slippery road surfaces. This assists in
providing directional stability and steering
performance of the vehicle under these
circumstances.
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
approximately 5 km/h (3 mph).
You may hear a 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 malfunction.
'98 Tacoma (U)
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. This will result in re-
duced braking performance.
The brake pedal pulsation caused by the
anti-lock brake system may indicate haz-
ardous road surface conditions. Although
the anti-lock brake system assists in pro-
viding vehicle control, it is still important
to drive with all due care, because the
anti-lock brake system cannot overcome
the laws of physics that act on your ve-
hicle:
"
Braking capability is dependent on tire
friction with the road surface.
to a speed below
"
Even though the anti-lock brake system
is operating, a driver cannot maintain
full control on certain slippery road sur-
faces, when cornering at high speeds,
or in violent maneuvers.
"
Avoid high speeds on wet roads. The
anti-lock brake system cannot eliminate
the risk of hydroplaning and loss of tire
friction.