What is the first step when removing the oil cooler from the engine?

Draining the coolant is the essential first step when removing the oil cooler from the engine. This step is crucial because it prevents coolant from spilling or leaking while you are disconnecting and removing components associated with the oil cooler. If the coolant is not drained, it can create a mess and potentially introduce contaminants or damage to the engine components when working in the area.

Once the coolant is safely drained, it becomes easier to handle the removal process of the oil lines and the cooler housing without worrying about coolant leaking out and causing injury or further complications in the maintenance task. Thus, initiating the process by draining the coolant ensures that the subsequent steps can be performed safely and efficiently.