Patent ID: 8160793

Claim:
A method for monitoring a status of a park brake of a vehicle brake system that includes a service brake system and a park brake system wherein, (i) the service brake system includes a service brake chamber that is delimited by a service brake displaceable wall upon which a brake pushrod is fixed, the brake pushrod is connected to a vehicle braking means and is capable of moving under a pneumatic pressure from a first position whereby the braking means are released to a second position whereby the braking means are actuated, (ii) the park brake system having actuating means capable of pushing the brake pushrod into its second position, wherein the method comprises: measuring an actual volume V of the service brake chamber; deriving from the actual volume V an actual park brake release status or a park brake actuated status, wherein measuring the actual volume of the service brake cylinder includes the steps of: applying a pneumatic test signal in the service brake chamber with a pneumatic test signal pressure remaining less than the pneumatic pressure that can actuate the brake, measuring a response pressure of the service brake chamber, comparing the response pressure of the service brake chamber against at least one threshold pressure value.