How Do I Put Together a Cosco Summit Car Seat?

The Cosco Summit car seat restrains children who weigh between 22 and 100 pounds or are 32 to 52 inches tall. It can be used as a high-back booster seat or as a five-point harness seat that is rear- or forward-facing. This car seat can be taken apart and put back together, which allows for it to be washed and converted from a five-point harness seat to a booster seat in a few steps. There is a proper way to reconstruct the five-point harness system after the car seat has been converted to a booster seat or after it has been taken apart to be washed.

Place the buckle strap through the slot on the base of the car seat. This will hook into place. Make sure the buckle strap is inserted completely and does not slip out. The buckle's red button needs to be facing out.

Replace the pad and cover of the car seat. There will be four elastic bands that will stretch over plastic hooks on the bottom sides and the top sides of the car seat. Before connecting the elastic straps, guide the buckle and side harness straps through the slots on the seat of the car seat padding. The pad and cover of the car seat are needed whether the car seat is used as a booster seat or as a five-point harness car seat.

Clip the top shoulder straps into the buckle. Slide the chest bar onto the shoulder straps.

Insert the shoulder straps through the top slots of the car seat. Use the screwdriver to help push the straps through the cover and plastic back slots of the car seat. The shoulder straps must be just above your child's shoulders, not behind the child's shoulders. There are three different shoulder strap slots from which to choose.

Attach the metal clip in the back of the car seat by sliding the shoulder straps over each side of the metal clip.

Adjust the tightness of the shoulder straps to fit snug against your child. You do not want the strap to be loose, as this will not restrain the child if an accident does occur.

Install the car seat into the car once all the straps and padding have been re-assembled.


As your child grows, the Cosco Summit car seat will grow with your child. It is important to adjust the settings of the shoulder straps whenever your child's shoulders move above the shoulder strap slots. This is also a great opportunity to clean the car seat.


It is very important to check that all connections and straps are securely attached before placing your child into the car seat.