What was found
LAS - DIVERSION - FLT 522 - C - EN ROUTE FROM PHX TO RNO FLIGHT CREW RECEIVED YELLOW HYDRAULIC SYSTEM FLUID LOSS INDICATION FOLLOWED BY FLIGHT CONTROL DEGRADATION TO ALTERNATE LAW, THIS WAS CAUSED BY LOSS OF NR 2 YELLOW YAW DAMPER, NR 1 YAW DAMPER PREVIOUSLY ON MEL. AIRCRAFT DIVERTED SAFELY TO LAS. MAINTENANCE TROUBLESHOT AND FOUND LEAK AT YELLOW HYDRAULIC PTU MANIFOLD QUICK DISCONNECT FITTING. REPLACED O-RING IAW CMM 29-10-05, LEAK TESTED GOOD. POST FLIGHT REPORT REVEALED ALTERNATE LAW WAS CAUSED BY FAILURE OF RT AILERON BLUE SERVO FOLLOWED BY YELLOW AILERON SERVO FAILURE.