The car seat base should be installed without the car seat attached. Follow instructions in the Rotating and Removing the Car Seat from the Car Seat Base to remove the car seat from the car seat base.
CHECK that the car seat base StrongArm is set to zero. If not, turn the StrongArm knob counterclockwise until the zero line is visible.
Remove the LATCH/UAS connectors from their storage locations by pressing the red buttons and pulling the connectors upward. For ease of installation, extend the LATCH/UAS belt to its maximum length by pressing the grey button on the belt adjuster and pulling on the belt.
Position the LATCH/UAS belt through the belt guides as shown. The logo on the LATCH/UAS connectors should be visible and facing outward when connectors are correctly routed.
LATCH/UAS should slide freely behind the lock-off clamp for installation
Pull LATCH/UAS belt left and right to check that it can slide freely behind the lock-off clamp.
If the vehicle seat back is adjustable, lock the vehicle seat back into the upright position.
Center the car seat base on the vehicle seat between the vehicle LATCH/UAS anchorages, making sure the areas under and behind the car seat base are clear of obstructions.
CHECK that car seat base is level by looking at the level indicator. The window in the level indicator must be green. If red appears in the window, try any of the following:
Remove the car seat base. Position a rolled towel under the car seat base, making sure the front of the car seat base contacts the vehicle seat. The towel should be compressed as the StrongArm tightens the car seat base into place.
Install the car seat base in a different vehicle seating position.
Attach both LATCH/UAS connectors to their corresponding vehicle anchorages. With the connector oriented with logo facing outward, push it straight onto the metal bar until you hear and feel a CLICK.
Pull out on each LATCH/UAS connector to be sure it is locked onto the vehicle anchorage.
Tighten the LATCH/UAS belt around the car seat base by pulling the LATCH/UAS beltloop to remove the slack from both sides of the lockoff clamp. Make sure the car seat base is not loose.
Turn the StrongArm knob at the front of the car seat base clockwise to activate the StrongArm mechanism.
As you’re turning the knob, the StrongArm mechanism is amplifying your strength and tightening the car seat base into the vehicle. Each installation varies slightly, but typically the knob can turn 10 full revolutions. After 10 full revolutions, check the car seat base for a tight installation. You know that you have reached the optimal tightness setting when you grasp with one hand and pull on the belt guides and the base upright does not move more than 2.5 cm (1 in) in any direction.