Which of the following actions should be performed last when parking an excavator?

The last action that should be performed when parking an excavator is removing the keys. This is essential for ensuring safety and preventing unauthorized use of the machinery. By removing the keys last, you ensure that the excavator is fully shut down and secured before you leave it unattended.

Prior to this step, the other actions should be completed in the proper order to ensure the safety and stability of the excavator. Securing the parking brake should be done to prevent any movement, then lowering the bucket helps to stabilize the equipment further and also places it in a safe state. Stopping the engine is an important step, as it ends the operation of the machinery, but if done before the other steps, it could leave the machine in an unstable position if the brake is not secured or if the bucket is not lowered. Therefore, removing the keys last is the most logical procedure to maintain safety and security.