What happens to the transmission system when you engage the clutch?

When you engage the clutch in a manual transmission vehicle, you effectively disconnect the engine from the transmission system. This action allows the engine to run while the vehicle remains stationary. Essentially, the engine continues to operate without transferring power to the wheels, which is crucial for changing gears. When the clutch is pressed down, it releases the pressure on the clutch plate, enabling the driver to shift gears without causing damage to the transmission.

The other options describe systems that are not directly impacted by the act of engaging the clutch. The brake system does not engage simply by pressing the clutch; rather, it operates independently based on the driver's actions. The torque converter relates to automatic transmissions, where it provides a fluid connection between the engine and transmission, and is not directly relevant to the manual clutch operation. Lastly, engaging the clutch does not affect the suspension system, which primarily deals with the vehicle's handling and comfort while in motion.