GMC 2010 T-Series Owner's Manual page 185

Air Dryer
If the 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. The integral purge tank has a
manual drain valve that must be drained every day. See
Air Brake Systems for the manual drain procedure.
The dryer is mounted on the driver side frame rail.
Electric Air Compressor
The vehicle might have an electric air compressor.
This compressor is used to run options that require
pressurized air, such as air horn or air seat.
The dryer has a filter that
needs changing at
intervals. See Scheduled
Maintenance on
page 6 5 for more about
servicing this filter.
The air compressor is used when vehicles do not have
an air brake system.
It is recommended that this system be drained on a
weekly basis.
Clutch Pedal Free Travel
Normal clutch pedal free play is 38 to 51 mm
(1.5 to 2 inches) measured from the floorboard. If the
free play is less than 32 mm (1.25 inches), adjustment
is required.
The air supply for this
system must be
maintained by releasing
the drain valve to eject
any moisture that could
have built up in the
system.
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