GMC 2005 T-Series Owner's Manual page 218

If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place and turn on your
hazard warning flashers.
CAUTION:
{
Your vehicle, when new, did not include tire
changing equipment or a place to store a tire
in the vehicle. Special tools and procedures
are required if a tire needs to be serviced. If
these tools and procedures aren't used, you
others could be injured or killed while trying to
change or service a truck tire.
Your truck, when new, did not include tire changing
equipment or a place to store a tire in the vehicle. Few
drivers of these vehicles have the necessary equipment
aboard to be able to change a flat tire safely. For
example, you would need a truck jack that can lift
several thousand pounds and a torque wrench that can
generate several hundred foot-pounds (Y) of
twisting force.
5-68
CAUTION:
{
If you try to put air back into a tire that has run
flat, even a tire that was quite low on air, the
tire can have a sudden air-out. This could
cause you to lose control of the vehicle and
have a serious crash. Don't refill a flat or very
low tire with air without first having the tire
taken off the wheel and checked for damage.
So if you're stopped somewhere by a flat or damaged
tire or wheel, you should get expert help. See Roadside
Assistance Program on page 0-0.