This SAE Recommended Practice establishes methods to determine grade parking performance with respect to: a. Ability of the parking brake system to lock the braked wheels. b. The trailer holding or sliding on the grade, fully loaded or unloaded. c. Applied manual effort. d. Unburnished or burnished brake lining friction conditions. e. Down and up grade directions. Purpose This document establishes a uniform procedure for determining the parking performance on a grade of any new trailer with manufacturer's maximum weight rating of more than 4540 kg (10 000 lb) intended for roadway use.