Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10399647) - 2016 - crc - 5/25/16
Instruments and Controls
81
The warning buzzer will stop
sounding when the parking brake is
engaged.
On diesel vehicles the brake low
vacuum warning light and warning
buzzer should come on to indicate
low vacuum reserve for brake power
assist. At the same time, the Back
up Electric Vacuum Pump operates.
4500 models are equipped with a
Back up Electric Vacuum Pump that
will turn on if brake booster vacuum
becomes insufficient.
If this happens while driving:
.
Do not pump the brakes. The
system is designed to stop the
truck with reserve power assist if
the pedal is held down. This
reserve is greatly reduced each
time you apply and release the
brakes.
.
Stopping distance may be
longer.
.
You may have to push much
harder on the brake pedal.
.
Have the vehicle repaired before
you continue driving.
The buzzer stops when the selector
lever is shifted to the N or P
positions.
{
Warning
Do not drive while the buzzer
sounds as the brakes are not
operating to their full capacity.
You and others could be seriously
injured.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine control switch is turned to
the ON position, and then should go
out after approximately
three seconds. If the light does not
come on, have it fixed so it will be
ready to warn if there is a problem.
This warning light comes on
together with the brake system
warning light whenever there is a
problem in the Anti-lock Brake
System (ABS). In this case, the ABS
stops working but the brakes still
function as ordinary service brakes.
{
Warning
If this warning light comes on
while driving, immediately stop
your vehicle at a safe place well
clear of traffic and take the
following actions.
1. Stop the engine.
2. Restart the engine. Check if
the ABS warning light
comes on and then goes
out. If it does, there is no
problem. The ABS operates
normally.
3. Move the vehicle slowly
forward. Gradually increase
the speed to 15 km/h
(9 mph). If the light goes off,
the ABS is normal.
(Continued)