B767-300 flight crew reported diverting following loss of the left hydraulic system.

Narrative:

[Enroute] we got left hydraulic qty alert. We observed left hydraulic fluid quantity continually and steadily decrease from 0.70 to 0.0. When quantity went to zero; we got a left hydraulic prim pump alert; with press light on left engine hydraulic pump; with left qty light on overhead panel. Complied with QRH for left hydraulic quantity and left hydraulic primary pump procedures. Engine driven pump was secured. Left hydraulic pressure remained at 3000 +/- 100 psi. Left hydraulic electric pump remained in automatic. [We advised] center; and a normal visual approach was conducted. Configuration to flaps 30; approach; rollout; and clearing runway were all normal. Fire/rescue looked over aircraft from their vehicles and found no irregularities. Captain elected to taxi in without escort. Taxi to parking was normal. All hydraulic systems performed normally to block in. Left system hydraulic quantity depleted to zero. Maintenance verified left hydraulic reservoir empty. No suggestions. This aircraft has approximately 2500 ttsn (total time since new). I wouldn't expect any hydraulic components to fail at this point in the airframe life.

Original NASA ASRS Text

Title: B767-300 flight crew reported diverting following loss of the left hydraulic system.

Narrative: [Enroute] we got L HYD QTY alert. We observed left hydraulic fluid quantity continually and steadily decrease from 0.70 to 0.0. When quantity went to zero; we got a L HYD PRIM PUMP alert; with PRESS light on left engine hydraulic pump; with left QTY light on overhead panel. Complied with QRH for left hydraulic quantity and Left Hydraulic Primary Pump procedures. Engine driven pump was secured. Left hydraulic pressure remained at 3000 +/- 100 PSI. Left hydraulic electric pump remained in AUTO. [We advised] Center; and a normal visual approach was conducted. Configuration to flaps 30; approach; rollout; and clearing runway were all normal. Fire/Rescue looked over aircraft from their vehicles and found no irregularities. Captain elected to taxi in without escort. Taxi to parking was normal. All hydraulic systems performed normally to block in. Left system hydraulic quantity depleted to zero. Maintenance verified left hydraulic reservoir empty. No suggestions. This aircraft has approximately 2500 TTSN (Total Time Since New). I wouldn't expect any hydraulic components to fail at this point in the airframe life.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1479775
Time
Date	201709
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Hydraulic Main System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe