GMC 2016 Sierra Owner's Manual page 117

116 Seats and Restraints
6. To tighten the belt, push down
on the child restraint, pull the
shoulder portion of the belt to
tighten the lap portion of the
belt, and feed the shoulder belt
back into the retractor. When
installing a forward-facing child
restraint, it may be helpful to
use your knee to push down on
the child restraint as you
tighten the belt.
Try to pull the belt out of the
retractor to make sure the
retractor is locked. If the
retractor is not locked, repeat
Steps 5 and 6.
7. If your child restraint has a top
tether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) 0 94 for more
information on using the top
tether anchors.
8. Before placing a child in the
child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the safety belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle safety belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.