What was found
RIGHT HYDRAULIC SYS EICAS & BRAKE SOURCE EICAS ON, WITH NORMAL SYS QTY & PRESSURE. CREW REPORTS BRAKE SOURCE LIGHT INFLIGHT WITH CORRESPONDING RT HYDRAULIC PRESSURE LIGHT. CREW NEVER NOTICED A RT HYD QTY DROP. TURNING OFF RT SIDE ENGINE PUMPS & RE-ENGAGING SWITCH, ALL INDICATIONS RETURNED TO NORMAL. BRAKE SOURCE LIGHT & PRESSURE LIGHT RETURNED AFTER A SUBSTANTIAL DELAY. TROUBLESHOOT IAW FIM 29-11, FAULT TREE 831. REMOVED AND REPLACED RT HYD PRESSURE SWITCH IAW AMM 32-35-51. OPS & LEAK CHECKED GOOD. FAULT ERASED. NO DEFECTS NOTED AT THIS TIME.