Oil change in older Doerr 1 hp twin cyl. air compr.
by walt odenwald
Each cyl. has what appears to be a drain plug and a vent right above the drain plug. my question is once you open the vent and then drain the oil it appears that you close the drain valve and fill the vent until the oil reaches the bottom of the hole. is this correct?
Note that each cyl. has what appears to be a drain and vent.