A method for manufacturing a face seal may generally include positioning a machining device relative to the face seal such that the face seal is compressed between a machining surface of the machining device and a support member on which the face seal is supported. In addition, the method may include removing material from a seal flange of the face seal using the machining device while the face seal remains compressed between the machining device and the support member and monitoring a compressive load applied through the face seal as material is being removed from the seal flange. Moreover, the method may include adjusting the operation of the machining device to prevent further removal of material from the seal flange when the monitored compressive load is equal to a predetermined load setting.