A lubricant injector includes a housing and a metering section attached to the housing. The housing includes a body and a metering cylinder extending from the body. The metering section includes a diaphragm disposed within the metering cylinder. The diaphragm forms a static seal between the metering cylinder and a lubricant pathway that extends through the body, and the diaphragm defines a metering chamber for measuring a volume of lubricant to be applied during a lubrication cycle. A retaining member secures the diaphragm within the metering cylinder.