A pneumatic power tool with a housing assembly, a pneumatic motor assembly, an output member, and a trigger assembly. The housing assembly has a body, a cap member and a gasket assembly. The body defines a motor cavity and an inlet manifold. The cap member defines an air inlet port. The gasket has a first portion being a band formed of a compressible material and a second portion formed of a porous material. The band of the first portion is sealingly abutted against the body and cap member. The pneumatic motor assembly is received in the motor cavity defined by the body. The output member is driven by the pneumatic motor assembly. The trigger assembly is coupled to the housing assembly and is operable for selectively operating the pneumatic motor assembly. Pressurized air received into the air inlet port is filtered by the second portion of the gasket assembly and flows into the inlet manifold when the pneumatic motor assembly is operated. A related method is also provided.