As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) NR 1 ENG HYD PUMP CAUTION LIGHT ILLUMINATED WITH FLAP RETRACTION ON TAKEOFF. NR 1 SPU TURNED OFF, MAIN PRESSURE DEPLETED TO 0 PSI. FLUID QTY REMAINED STEADY. A/C RETURNED TO YYZ. INPUT SHAFT SHEARED FROM AN INTERNAL FAILURE. PUMP DISMANTLED. INTERNAL DAMAGE FROM 2 BROKEN PISTONS (PN 404783), CAUSING DAMAGE TO OTHER PARTS. (PISTON SHOE PLATE PN 396386 & RETAINER PN 405892) ALSO HARDWARE DAMAGE NOTED.