The article presents a modified method of evaluating the braking efficiency of a motor vehicle when examined on a roller brake tester with a load lower than the vehicle load capacity. For vehicles having no pressure sensor in the braking system, a modification to the existing method of extrapolation of measurement results has been proposed. For vehicles with an ESP system, provided with a pressure sensor incorporated in the hydraulic braking system, and for electrohydraulic brakes, a new calculation procedure has been proposed for checking the braking efficiency coefficient. This procedure consists in simultaneous measurements of pressure in the hydraulic system and braking forces on the roller brake tester, followed by calculation of the pressure that would generate the braking forces corresponding to the required braking efficiency. Finally, a check is made to see if the hydraulic system generates the calculated pressure when a force applied to the brake pedal not exceeds the acceptable value.