I'm fully aware of the procedures Aidie but I am challenging this use of the park brake which is not designed for this level of mis-use. The service brakes are much more powerful, generally self adjusting and will hold the truck more securely than a park brake. Operators should be trained to apply the service brakes securely when making hydraulic movements. If you study any application, operators in the real world do not practice what they have been taught. Once they get their license, the park brake is generally used as designed but in not promoting the use of the service brakes whilst making hydraulic movements, we lose the opportunity of ensuring safe practice. The use of the park brake as enforced by the training agencies is non-sensical, impractical and ripe for review.