Abstract: An improved oil filter crusher unit is provided for use in recovering used motor oil from an oil filter of the type used in automotive vehicles and for reducing the volumetric size of an oil filter prior to disposal with other trash in a landfill or the like. The crusher unit includes a crushing piston assembly having a pneumatic piston connected via a bearingless piston shaft to a filter crushing head. An air circuit system provides pressurized air to the piston assembly to advance the crushing head into engagement with an oil filter disposed within a crushing chamber. A control lever on the outside of the unit mechanically interlocks with a safety door to prevent access to the crushing chamber during unit operation. In addition, the geometry of the crushing head incorporates one or more protrusions which initiate filter crushing by crimping localized areas of the filter and thereby weaken the filter so that crushing can be accomplished with relatively low peak crush forces.