摘要 |
A vehicle park-brake system includes a park brake, a solenoid; a first pressure source; a servo for disengaging the park-brake using the first pressure source, and for disengaging the park-brake using a force produced by the solenoid that actuates first and second pistons; and a second pressure source applied to the servo causing hydraulic pressure to vent from the servo, the pistons to detach mutually, and the servo to engage the park brake. |