What was found
(CAN) AT 18,000 NR 1 ENG HYD PUMP CAUTION LIGHT ILLUMINATED. COMPLETED THE REQUIRED CHECKLIST, THE NR 1 HYD ISO VLV CAUTION LIGHT ILLUMINATED ALONG WITH INBD ROLL SPLR & NR 1 RUD HYD & NO FLUID IN THE NR 1 HYD SYS. RAN THE NR 1 HYD SYS FAILURE CHECKLIST. UPON INSPECTION OF THE NR 1 ENG, IT WAS CLEAR THERE WAS FLUID LEAKING ALL OVER THE COWLING & FROM THE ENG INTAKE. INVESTIGATION REVEALED CATASTROPHIC INTERNAL DAMAGE & A HOLE IN THE CASE OF THE NR 1 EDP, WHICH ALLOWED HYD FLUID TO ESCAPE TO ATMOSPHERE. THE NR 1 EDP WAS REPLACED, THE ASSOCIATED ABBREVIATED FLUSH PROCEDURE WAS ACCOMPLISHED & THE ACFT WAS RETURNED TO SERVICE, THE NEXT DAY, 09 JULY 2015. THE FULL FLUSH PROCEDURE IS REQUIRED WITHIN 10 FLIGHT HOURS & WAS SCHEDULED FOR THE FOLLOWING DAY.