Chevrolet T-Series Owner's Manual page 210

Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with the brakes.
Brake linings should always be replaced as
complete axle sets.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its
many parts have to be of top quality and work well
together if the vehicle is to have really good
braking. Your vehicle was designed and tested with
top-quality GM brake parts. When you replace parts
of the braking system — for example, when the
brake linings wear down and you need new
ones put in — be sure you get new approved
GM replacement parts. If you do not, the brakes
may no longer work properly. For example, if
someone puts in brake linings that are wrong for
your vehicle, the balance between the front and
rear brakes can change — for the worse. The
braking performance you have come to expect can
change in many other ways if someone puts in the
wrong replacement brake parts.
210
Air Brake Systems
If your vehicle has air brakes, it is important to get
rid of moisture in the system. Moisture will
damage the system if it is not removed daily.
There are two ways to do this. One is automatic
through the air brake vehicle's air dryer with integral
automatic moisture ejector that purges air from the
system through a self-contained reservoir. The
other way to drain moisture from the air brake
system is to manually activate drain valves at each
reservoir. Drain the air reservoirs occasionally to be
sure the air dryer is working properly.
Drain them at full system pressure. To be sure
you are at full pressure, check the air pressure
gage. It should read at least 100 psi (692 kPa).
Air Dryer
If your vehicle has air brakes, it will have an air
dryer. This collects and removes dirt, moisture, or
other foreign matter from the air prior to entering
the brake system. The air dryer also serves
as a moisture ejector. It automatically ejects the
moisture when the compressor cycles.