GMC 2004 Sierra - Manual (Page 318)

When you are back on roads, though, be sure to
replace the air dam.
Notice: Operating your vehicle for extended
periods without the front bumper lower air dam
installed can cause improper air flow to the engine
and may allow things like fog lamps or tow hooks
on the front of your vehicle to be damaged. Always
be sure to replace the front bumper air dam when
you are finished off-road driving.
To reinstall the lower air dam, do the following:
1. Line up each push-pin
with its intended
retainer and push the
washer portion of
the push-pin toward
the retainer until it locks
into place.
2. Push the flat end of the
push-pin toward the
retainer until it
locks into place,
making sure each is
secure.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if so equipped) are properly
attached. Be sure you read all the information about
your four-wheel-drive vehicle in this manual. Is
there enough fuel? Is the spare tire fully inflated? Are
the fluid levels up where they should be? What are the
local laws that apply to off-roading where you will be
driving? If you do not know, you should check with law
enforcement people in the area. Will you be on
someone’s private land? If so, be sure to get the
necessary permission.
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