Method of assessing the influence of the moisture content in the braking fluid on the braking system actuation efficiency

Abstract

Abstract The paper deals with assessing the influence of the braking fluid composition on the time of braking system actuation. It is justified that this factor should be taken into account in expert investigations of road accidents. The idea behind the research deals with putting forward proposals for improving the method for reconstructing road accidents by taking into account the braking fluid composition which can change during operation, resulting in increasing the time of brake drive actuation and in increasing the stopping distance of a vehicle equipped with a hydraulic braking system. The method of road accident reconstruction by adjusting standard (reference) values of braking parameters with consideration for properties of the braking fluid, affecting the time of deceleration rising up to its maximum and braking time with respect to steady deceleration, is reviewed. Experiments established the influence of the boiling temperature of the braking fluid and the moisture content on the total time of braking system actuation. A coefficient taking into account the influence of these factors on the estimated braking time and stopping distance of a vehicle is proposed and scientifically justified. The value of the paper lies in method application by automobile technical experts for the purposes of improving objectivity of expert evaluation results. The suggested refinements to the method allow improving and expanding the evidence base in road accident reconstruction in terms of the technical possibility to prevent the road accident, related to evaluation of the actual technical condition (as of the moment of the road accident) of the braking system equipped with a hydraulic drive.