What was found
(CAN) DURING FLIGHT #2 ENGINE OIL QUANTITY DECREASED SLOWLY FROM 6 TO 2 READING. MAINTENANCE ADVISED TO CONTINUE IF TEMPERATURE AND PRESSURE NORMAL. LATER QUANTITY REACHED "0" AND SLOWLY PRESSURE DROPPED TO 20 PSI DIFFERENTIAL. AIRCRAFT DIVERTED. POST FLIGHT INSPECTION FOUND THE #2 ENGINE MAIN OIL LINE BETWEEN THE FILTER AND THE LUBE UNIT CRACKED AT THE 6 O'CLOCK POSITION UNDER THE CLAMP. CRACKED LINE REPLACED, OIL SYSTEM SERVICED AND ENGINE GROUND RUN SERVICEABLE WITH NO LEAKS.