Abstract: Various examples of brake actuators are provided. In one example, a brake actuator includes a parking brake chamber defined by a spring housing and an adapter base. The parking brake chamber includes a parking diaphragm that has an opening and the parking diaphragm is disposed between the spring housing and the adapter base which divides the brake spring chamber into a spring volume and a release volume, with the spring volume of the brake spring chamber being sealed from atmosphere. The parking brake chamber also includes a piston that is disposed in the spring volume and is in contact with the parking diaphragm, and the piston includes a piston passageway through the piston to allow air flow between the release volume and the spring volume.

Abstract: Various embodiments of a method, system and controller for determining whether to actuate the service brakes of a trailer are disclosed. In accordance with one aspect, the controller includes an input for receiving a stop lamp signal from an associated tractor, an input for receiving a control line pressure signal of the trailer, a control output for transmitting a braking control signal and control logic. The method includes receiving a stop lamp signal, receiving a control line pressure signal and determining whether to transmit a braking control signal to the service brakes of the trailer in response to the stop lamp signal being on and the control line pressure signal being less than a pressure threshold.

Abstract: A plug for sealing an aperture in a brake actuator housing is provided that provides improvements in installation and retention of the plug and protection for sealing surfaces. The plug includes a retention member including a body defining an aperture configured for alignment with the actuator housing aperture along an axis extending through the apertures. The retention member further includes a plurality of alignment tabs extending radially from the body. The tabs are configured to be received within a plurality of notches formed in a retaining ring affixed to the housing when the retention member is disposed in an unlocked position and configured to be disposed on a first side of the retaining ring when the retention member is rotated about the axis to a locked position. The plug further includes a seal configured to be received within the aperture in the body. The seal closes the second aperture.

Abstract: Various examples of brake actuators are provided. In one example, a brake actuator includes a parking brake chamber defined by a spring housing and an adapter base. The parking brake chamber includes a parking diaphragm that has an opening and the parking diaphragm is disposed between the spring housing and the adapter base which divides the brake spring chamber into a spring volume and a release volume, with the spring volume of the brake spring chamber being sealed from atmosphere. The parking brake chamber also includes a piston that is disposed in the spring volume and is in contact with the parking diaphragm, and the piston includes a piston passageway through the piston to allow air flow between the release volume and the spring volume.

Abstract: A plug for sealing an aperture in a brake actuator housing is provided that provides improvements in installation and retention of the plug and protection for sealing surfaces. The plug includes a retention member including a body defining an aperture configured for alignment with the actuator housing aperture along an axis extending through the apertures. The retention member further includes a plurality of alignment tabs extending radially from the body. The tabs are configured to be received within a plurality of notches formed in a retaining ring affixed to the housing when the retention member is disposed in an unlocked position and configured to be disposed on a first side of the retaining ring when the retention member is rotated about the axis to a locked position. The plug further includes a seal configured to be received within the aperture in the body. The seal closes the second aperture.

Abstract: Various embodiments of a method, system and controller for determining whether to actuate the service brakes of a trailer are disclosed. In accordance with one aspect, the controller includes an input for receiving a stop lamp signal from an associated tractor, an input for receiving a control line pressure signal of the trailer, a control output for transmitting a braking control signal and control logic. The method includes receiving a stop lamp signal, receiving a control line pressure signal and determining whether to transmit a braking control signal to the service brakes of the trailer in response to the stop lamp signal being on and the control line pressure signal being less than a pressure threshold.