B767-300 and 300 ER
Workload; Troubleshooting; Time Pressure
Aircraft Equipment Problem Critical
Flight Crew Diverted; General Flight Cancelled / Delayed
Aircraft
Approximately one hour into the flight I noticed the right engine oil quantity was at 0. I checked pressure and temperature on the right engine and pressure was normal 30 psi. So I thought maybe it was an indication issue. After about 20 minutes Pressure was down to 24-25psi. I Arinc'd Dispatch and Maintenance Control to get them in the loop and the response from Maintenance was 'follow your procedures'. Since I had no EICAS I continued. After another 15 minutes we were down to 18 PSI and the indicator was now yellow and psi was still slowly dropping. I called Dispatch back and initiated discussion on diversion as I was coming up on the Rocky Mountains and was obviously slowly losing oil PSI and had reviewed the QRH and knew if it got to red line it was a mandatory shutdown and there was over 2 hours left to fly.My thought process was to error on the side of safety and try to get the airplane on the ground before I would be forced to shut down the engine over the Rockies and put my crew and plane into a potential emergency situation. Dispatch gave us  a good place to take the plane. Approach and landing was normal and upon landing Oil PSI was at 12 PSI. After block in it was determined oil tank was empty; and oil was leaking out of the bottom of the case at the rear of the right engine. Direct communication to the Chief Pilot or Duty Pilot to get another opinion and perspective would have helped in making communications go more smoothly.
A pilot reported diverting due to an oil leak in one engine.