What was found
(PIREP) NR 1 MAIN HYD PRESSURE INDICATOR READ BELOW 3000 PSI THEN DROPPED TO ZERO APPROX 5 MIN. CAME BACK UP TO 3000 PSI THEN DOWN TO 2000 AND BACK TO 3000 PSI TIL LANDING AND PARK. (MX - OGG) GROUND RUN, OPS CHECK DETERMINED NR 1 HYD INDICATING SYSTEM INTERMITTENT. AIRCRAFT APPROVED FOR FERRY FLIGHT FROM OGG TO HNL ONLY. (MX - HNL) REMOVED AND REPLACED NR 1 MAIN HYD PRESS INDICATOR. SECURED CANNON PLUG AND SECURED SCREW. OPS CHECK GOOD IAW DHC 29-30-00, PG 1 PAR 2.