What was found
RIGHT HYD QTY LOW PER CREW DEBRIEF, APPEOX 2 HRS INTO FLT, HYD QTY STARTED TO DECREASE & NOT FLUCTUATE ON ARRIVAL QTY IND SHOWS .39 WITH BRAKES SET MATCHING HYD SERVICE PANAL GAUGE. ON ARRIVAL PERFORMED GVI OF RT MLG, WINGS, & BELLY OF A/C WITH NO NOTIABLE LEAKS FOUND. HYD QTY ON CENTER & LT TANK READS 0.95. SERVICED RT HYD UP TO 0.86 & FOUND HYD LEAK ON RT ELEVATOR. REMOVED MOST OTBD PANEL (345HB) FOR PCA INSPECTION & FOUND NO HYD LEAKS AT MOST OTBD PCA. WHEN HYD RAN & ELEVATORS MOVED FOUND VERY HEAVY MIST FROM MIDDLE PCA ENCLOSURE. AFTER MIDDLE PCA PANEL (345GB) REMOVED & OPERATED SYS AGAIN & FLT CONTROL WAS UNABLE TO DUPE MIST. INSPECTED ALL HYD LINES WITH NO FAULTS. SUSPECT EITHER MIDDLE PCA COLD SOAKED & OR ROD END SEAL. RESEALED & STOPPED HYD LEAK. DUE TO UNABLE TO DUP FAULT WITH MIDDLE PCA SUGGEST MIDDLE PCA REPLACEMENT OR FURTHER TESTING. REMOVED RT SYS, RT ELEVATOR (MIDDLE PCA ) IAW AMM 27-31-05-424-027 , C/W RII REQUIREMENT FOR ATTACH POINT. INSTALLED RT SYS RT ELEVATOR (MIDDLE PCA) IAW AMM 27-31-05-424, OPS & LEAK CKD GOOD.