A system and method for detecting a pre-charge pressure of a hydraulic braking system are disclosed. A controller receives pressure readings from a pressure sensor indicative of the pressure of a hydraulic brake accumulator or the lower pressure of more than one accumulator. In response to fluid being provided to the hydraulic accumulator, the controller determines a first rate of pressure change, a second rate of pressure change different than the first rate, and a transition pressure between the first and second rates. The controller determines an approximate pre-charge pressure of the hydraulic brake accumulator based on the transition pressure. A warning can be provided to the operator or another when the determined pre-charge pressure is lower than a reference pressure.