What was found
DURING DESCENT, BOTH LT & RT HYD PRESS ANNUNCIATORS ILLUMINATED. THE INDICATION WAS BACKED UP BY THE HYD PRESS GAUGE INDICATING 0 PSI. DUE TO THE LOSS OF HYD POWER & WEATHER CONDITIONS THE ACFT WAS DIVERTED. PERFORMED A MANUAL EXTENSION OF THE LG & LANDED WITHOUT INCIDENT. INSPECTION REVEALED A CRACK IN FLAP UP LINE IN LT NACELLE. REPLACED THE CRACKED HYD LINE IN LT NACELLE WITH NEW LINE & REPLACED BOTH ENG DRIVEN HYD PUMPS. SERVICED SYS & PERFORMED OPERATIONAL CHECKS OF THE HYD SYS, ALL CHECKS WERE NORMAL.