An exhaust rocker assembly for operating an exhaust valve of an engine during a compression-release engine braking operation. The exhaust rocker assembly comprises an exhaust rocker arm and a self-contained compression brake control module (CBCM) mounted to the exhaust rocker arm and operatively coupled to the exhaust valve for controlling a lift and a phase angle thereof. The CBCM includes a casing, an actuation piston disposed outside the casing so as to define an actuation piston cavity, a reset check valve provided between the casing and the actuation piston, and a compression brake actuator disposed in the casing. The actuation piston reciprocates relative to the casing. The compression brake actuator includes a control piston. The control piston engages the check valve when deactivated so as to unlock the actuation piston cavity and disengages from the check valve when activated so as to lock the actuation piston cavity.