Most modern vehicles incorporate the use of gas struts or gas springs to lift the boot lid up and keep it open. If these springs on the boot are worn and there is a loss of pressure or resistance in the spring, it will no longer be able to stay open, or hold the boot lid open. This is when new gas springs need to be fitted to the vehicle. The first step to changing these springs is to search online and punch in the model, make and engine size of your vehicle, after which it can be determined quite easily which gas spring is required for your particular vehicle.
Gas springs operate quite simply with a form of hydraulic pressure. When the boot lid is closed there is a build up of pressure within the spring and when the vehicle boot is opened, this pressure is released, allowing the spring to expand, and opening the boot and holding it open. Gas springs for the boot are usually not expensive to purchase and they are very easy to fit. They are usually secured with small clips that are easily removable and this makes the fitment of the new component very easy.
Once a gas spring has lost its elasticity it can become very dangerous when opening the boot of the car. If the springs are not working properly, there is every possibility that the boot lid can fall onto the hands of the person opening the boot and cause severe bodily harm. A heavy boot lid with a worn gas spring can break an arm quite easily. So, be sure to change any gas spring that you find to be faulty.