Abstract: This is a reliable long-lasting removable seal for attachment to the push rod opening of a service brake actuator that is to be used with a disc brake system. The seal allows the service brake actuator to enjoy the benefits of having breather holes in its housing wall while preventing any unwanted contaminants brought in through such holes from being transmitted to the attached disc brake mechanism. The seal is a hollow molded piece in the form of a tubular insert made of a slightly deformable material that fits into the central opening in the lower service brake housing through which the push rod extends. Flanges on the insert sealingly engage the wall of the service brake housing, and a central bore sealingly engages the push rod. The insert may include a separate internal bushing made of durable material which supports at least one annular seal for engaging the push rod.

Abstract: Disclosed is an easily removable and replaceable filter for attachment to the breather holes in the housing of a spring or service brake actuator. The invention has a hollow shaft and flange for snap fitment into a brake actuator breather hole, and includes a plurality of ventilation openings and a membrane made of material which allows air to pass into and out of the spring brake housing, while keeping foreign material out. The present invention may be easily adapted for use on any of a large number of existing spring or service brake housing assemblies (including piston, diaphragm, dual-diaphragm, dual-piston, and/or piston & diaphragm) at minimal cost. When the filter(s) of the present invention are installed, any unused breather openings in the spring brake housing should be plugged so that all air is filtered through the membrane in the filter.