If your Chevrolet trunk or rear lift gate doesn't stay open or closes when you open it the problem is weak trunk supports. These are gas-filled struts and can wear out over time. As they weaken they no longer support the weight of your Chevrolet trunk lid or liftgate. The good news is that you can change Chevrolet trunk struts yourself.
Park your Chevrolet on a level surface and set the parking brakes. Turn off the ignition.
Open the trunk or the lift gate and have a friend hold up the trunk as you remove the rear gas struts.
Locate the trunk struts that need to be replaced.
Locate the clip that locks the trunk support locks to the ball joint.
Use a flat screwdriver to pry out the clip that locks the trunk strut in place. Follow the same procedure for the other end. Install the new trunk support in reverse order.