A fluid level indicator and method of determining a fluid level. In one example, a fluid level indicator is configured to be disposed in a brake fluid reservoir of a vehicle. A motor drives the fluid level indicator at a constant horsepower. A motor sensor monitors the speed of the motor. A controller receives the motor speed data from the motor sensor and receives vehicle movement data from other vehicle sensors. The controller determines the level of the brake fluid based on the motor speed and the vehicle movement data.

The present disclosure relates to a method for testing a brake fluid sensor of a vehicle braking system, wherein the brake fluid sensor can indicate the fluid level in the fluid reservoir, wherein the method has the following steps: (1) Altering the fluid level in at least one region of the at least one fluid reservoir by means of at least one braking force generating device; and (2) Detecting whether the at least one brake fluid sensor emits a signal indicating the modified fluid level in the at least one region of the at least one fluid reservoir.

The present disclosure relates to a control method of a brake system including a reservoir in which oil is stored, wherein the control method includes detecting a first level of a liquid level of oil stored in the reservoir, detecting a second level of the liquid level of oil stored in the reservoir, determining a decrease trend of an oil amount stored in the reservoir based on a time point when the first level is detected and a time point when the second level is detected, and limiting at least one additional function based on the decrease trend of the oil amount.

A filling level sensing device for a liquid reservoir, in particular for a compensation tank of a vehicle brake system, includes at least one float, at least one sensor element connected to the at least one float, and at least two sensors for detecting the position of the at least one sensor element. The float may be designed to come into contact with the liquid in the liquid reservoir. At least one of the two sensors may sense a change in the filling level of the liquid reservoir depending on the position of the at least one sensor element relative to the at least two sensors.

A method and a system for monitoring wear of a braking frictional pad of a motor vehicle, includes stopping the motor vehicle stably on a horizontal or substantially horizontal plane; determining a current fluid level in a brake fluid reservoir; determining a volume difference (ΔV.sub.L) of the brake fluid in the brake fluid reservoir by comparing the determined current fluid level with a predetermined reference fluid level; when a thickness loss of a braking frictional pad equipped for a front vehicle wheel or a rear vehicle wheel is known, determining a thickness loss of a braking frictional pad assigned for the other front vehicle wheel or the other rear vehicle wheel based on the volume difference of the brake fluid in the brake fluid reservoir and a diameter of a brake piston of the respective brake device.

A brake device for a vehicle includes a fluid supply portion that supplies a fluid to a wheel cylinder utilizing the fluid in a reservoir and is configured such that a piston presses brake pads against a disc rotor to apply a braking force to a wheel. The brake device includes: a fluid level sensor configured to measure a value of a fluid level in the reservoir and a controller including one or more processors and configured to: estimate a wear amount of the brake pads based on a result of measurement by the fluid level sensor; estimate a heat generation amount of the brake pads based on the result of measurement; and determine whether a fluid leakage is occurring based on i) an amount of change in the fluid level that is based on the result of the measurement, ii) the wear amount, and iii) the heat generation amount.

A hydraulic disc braking system is disclosed. The system has a manually operated control device for a cyclist to issue a braking command. The system has a master cylinder assembly having a membrane dividing the hydraulic fluid tank into a variable volume filled chamber and a complementarily variable volume empty chamber. A membrane detector senses the presence of the membrane relative to a predetermined position in the tank and/or a meter measures the distance of the membrane from the ceiling of tank.

A diagnostic method for a bicycle hydraulic disc braking system, having a master cylinder assembly with a cylinder inside which a piston reciprocates against the action of a return spring. The master cylinder has a hydraulic tank with a bottom, a ceiling, and a membrane that divides the hydraulic tank into two chambers. The hydraulic tank is connected to the cylinder through the bottom. A metering device measures the distance between the membrane and the ceiling of the tank. The output signal of the metering device is evaluated to determine that operation is correct when the membrane temporarily approaches the ceiling by a predetermined extent range, or incorrect otherwise. A positive evaluation reflects the correct operating condition, and a negative evaluation reflects an incorrect operating condition.

A method for operating a brake system for motor vehicles, comprising a master brake cylinder actuable by a brake pedal, an electrically controllable pressure provision device, a pressure medium reservoir tank, from which the master brake cylinder and the pressure provision device are supplied with pressure medium, and at least two hydraulically actuable wheel brakes and at least one electrically actuable inlet valve per wheel brake, wherein the wheel brakes are actuable either by the master brake cylinder or by the pressure provision device, the pressure medium reservoir tank is monitored by a device for determining a level of the pressure medium, wherein the wheel brakes are divided into at least one first wheel brake group and one second wheel brake group, and wherein the inlet valves of the first wheel brake group are closed when the determined level falls below a first limit value (s.sub.1).

A second control unit controls a pump of a P system and a pump of an S system according to a stroke of a brake pedal that is detected by a stroke sensor in a state that a fluid level of brake fluid in a reservoir tank falls below a predetermined fluid surface level.