Chevrolet 2007 Kodiak Owner's Manual page 300

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.
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.
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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 the air brakes 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 has an air dryer
mounted on the passenger side frame rail. This
collects and removes dirt, moisture, or other foreign
matter from the air prior to entering the brake
system. The dryer also acts as a moisture ejector.
It automatically ejects the moisture when the
compressor cycles. The purge tank has a manual
drain valve that must be drained every day. See
"Air Brake Systems" for the manual drain procedure.
The dryer has a filter that you need to change at
intervals. See Scheduled Maintenance on page 363
for more about servicing this filter.