The Effect of Brake System Evacuation and Fill on Initial Brake Pedal Travel

The effectiveness of a brake system evacuation and fill will be shown to be quantifiable in terms of initial brake pedal travel by way of a few simple hand calculations. This paper does not discuss the mechanics of evacuation and fill, rather, it is a study into the impact of the evacuation and fill process upon initial brake pedal travel. First, initial pedal travel due to the evacuation and fill process will be quantified by a series of calculations. Secondly, empirical data will be presented which will demonstrate the close correlation of calculated results to those obtained in actual brake system tests.