Slide Piston Function

When vehicle is used on rough roads where tires sometimes lose adhesion, ABS may function excessively, causing an excessively large volume of brake fluid to flow into chamber C. As this occurs, piston is moved excessively, resulting in an abnormal loss of pressure in chamber B. In order to overcome this problem, slide piston is kept in proper position by spring force to avoid a negative pressure in chamber B. See Figure .