Abstract: A brake system for a vehicle including: a brake caliper; a brake fluid container connected to a brake pipe; a brake hose connecting the brake pipe to the brake caliper; a refractometer arranged in the proximity of the brake caliper and configured to measure a refraction of the brake fluid at the brake caliper; a temperature sensor arranged in the proximity of the refractometer and configured to measure a temperature of the brake fluid in the proximity of the brake caliper; and a control unit configured to determine a water content of the brake fluid based on the measured refraction and the measured temperature.

Abstract: A method for estimating water content of brake fluid in a brake system including brake calipers and a brake fluid container, the brake calipers and the container each including a sensor configured to detect a water content of the brake fluid, the method including: arranging the brake system in a controlled environment; for a predetermined time period, exposing the brake system to a controlled temperature and humidity such that an increase in water content in the brake fluid is accelerated; determining the water content of the brake fluid in the brake fluid container and in each brake caliper as a function of time; and based on the determined water content as a function of time, establishing a model describing the relation between the water content of brake fluid in a brake caliper and the water content in the brake fluid in the brake fluid container.

Abstract: A brake system for a vehicle including: a brake caliper; a brake fluid container connected to a brake pipe; a brake hose connecting the brake pipe to the brake caliper; a refractometer arranged in the proximity of the brake caliper and configured to measure a refraction of the brake fluid at the brake caliper; a temperature sensor arranged in the proximity of the refractometer and configured to measure a temperature of the brake fluid in the proximity of the brake caliper; and a control unit configured to determine a water content of the brake fluid based on the measured refraction and the measured temperature.

Abstract: A method for estimating water content of brake fluid in a brake system including brake calipers and a brake fluid container, the brake calipers and the container each including a sensor configured to detect a water content of the brake fluid, the method including: arranging the brake system in a controlled environment; for a predetermined time period, exposing the brake system to a controlled temperature and humidity such that an increase in water content in the brake fluid is accelerated; determining the water content of the brake fluid in the brake fluid container and in each brake caliper as a function of time; and based on the determined water content as a function of time, establishing a model describing the relation between the water content of brake fluid in a brake caliper and the water content in the brake fluid in the brake fluid container.