What should be done after the hydraulic line is reattached when proof loading?

After reattaching the hydraulic line when proof loading, it is important to rewind tape and bleed the brakes. Bleeding the brakes ensures that any air trapped in the hydraulic system is removed, which is critical for maintaining proper brake function and safety. Air in the hydraulic lines can lead to spongy brake performance and can compromise the reliability of the braking system.

By rewinding the tape, you also keep everything organized and ensure that no debris enters the hydraulic line, which could further affect performance. This step also signifies that the hydraulic line is properly secured and ready for operation. Overall, this process helps ensure that the hydraulic system is functioning correctly, which is vital after making any changes, such as reattaching lines.

Other options might involve important tasks, but they do not address the immediate necessity of ensuring that the hydraulic system is devoid of air, which is crucial for effective operation.