OTHER FEATURES
about reading and interpreting diagnostic codes,
refer to chapter 8, "Technical Information" under
"World Transmission Diagnostic Codes".
TRANSMISSION RETARDER
The transmission retarder is an optional device
that helps to reduce the speed of a vehicle. It
improves vehicle control, increases driving
safety and permits more economical operation.
The retarder provides slowing power when it is
most needed, such as when descending
mountain roads, in stop-and-go traffic and on
crowded freeways.
The retarder is provided with a switch on the
dashboard and a lever on the steering column
(refer to "Controls & Instruments" chapter 3).
Note
:
Extended use will raise the
temperature of the transmission oil.
The retarder helps to reduce speed on grades
without using the vehicle's conventional service
braking system. This virtually eliminates brake
overheating and reduces the risk of a runaway
vehicle. A retarder greatly increases the service
life of brake pads and discs, resulting in reduced
brake maintenance costs.
Note:
Each time the transmission retarder
system is in operation, the stoplights
automatically illuminate.
Note:
For vehicles equipped with the Antilock
Braking System (ABS), as the wheels start to
lock-up on slippery roads, the output retarder
automatically deactivates until the wheels roll
freely.
JACOBS ENGINE BRAKE
The JACOBS engine brake is an optional diesel
engine retarder which uses engine compression
to aid in slowing and controlling the vehicle.
When activated, (refer to "Controls &
Instruments" chapter 3) the JACOBS brake
alters the operation of the engine's exhaust
valves so that the engine works as a power-
absorbing air compressor. This provides a
retarding action to the wheels.
The engine brake is a vehicle-slowing device,
not a vehicle-stopping device. It is not a
substitute for the service braking system. The
service brakes must be used to bring the vehicle
to a complete stop.
Effectiveness of the engine brake system will
vary according to the transmission range in use.
The engine brake system is more effective in
lower ranges and at higher engine speeds.
Warning:
When descending significant grades,
use the service brakes as little as possible. If
the engine does not slow the vehicle to a safe
speed, apply service brakes and shift to a lower
range. Let the engine (and engine brake) slow
the vehicle. Keep brakes cool and ready for
emergency stopping.
Note:
Each time the engine brake system is
in operation, the stoplights automatically
illuminate.
ANTI-LOCK BRAKING SYSTEM
The purpose of the Anti-lock Braking System
(ABS) is to maintain vehicle stability and control
during braking and to minimize the stopping
distance in any road condition.
On slippery roads and more generally in
emergency situations, over-braking frequently
induces wheel locking. Wheel locking greatly
increases breaking distance on any road
surface. Locked wheels also impede directional
control and cause severe tire abrasion. An anti-
lock braking system provides maximum braking
performance while maintaining adequate control
on slippery roads.
The basis of ABS is constant monitoring of
wheel parameters during braking. Sensors on
each wheel of the front and drive axles
constantly measure wheel speed during braking.
This information is transmitted to a four-channel
electronic processor which senses when any
wheel is about to lock. Modulating valves quickly
adjust brake pressure (up to 5 times every
second) to prevent wheel lock. Each wheel is
therefore controlled according to the available
grip.
In this way, the vehicle is brought to a stop in the
shortest possible time while remaining stable
and under the driver's control.
Caution:
Vehicles following ABS-equipped
vehicles may not be able to brake as fast on
slippery roads. Whenever possible, warn other
drivers by depressing the brake pedal lightly
several times before braking.
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