What was found
AIRCRAFT GROUNDED. NEARING TOP OF DESCENT, MASTER CAUTION HYD ILLUMINATED. ENGINE 1 HYD PRESS BEGUN FLICKERING. HYD PRESS REMAINED AT 3000 PSI ON DISPLAY. RAN QRH FOR SYSTEM AND RETRACTED GEAR MANUALLY. LAL R & R NR 1 ENGINE EDP, IAW FOR B737 AMM 29-11-11-000-801. NO LEAKS NOTED.