What was found
DURING TAXI AILERON LOCK OUT MESSAGE AND SELECTED FLAPS 5 AND TE DISAGREE EICAS AND FLAPS DID NOT EXTEND PAST FLAPS 5. AIRCRAFT RETURNED TO BLOCK AND WAS GROUNDED BY MAINTENANCE. MAINTENANCE PERFORMED OPS CHECK OF AILERON LOCKOUT SYSTEM IAW B767 AMM 27-11-44. OPS CHECK GOOD, MESSAGE REMAINED CLEARED. RESET FSEU, NO FIX PERFORMED BITE OF FSEU. NO DEFECTS NOTED. INSPECTED FLAPS BYPASS VALVE. FOUND STUCK IN BYPASS CLEANED CANNON PLUG IAW B767 20-30-02 SOPM. LUBRICATED TE FLAP BYPASS VALVE AND ADJUSTED TILL SMOOTH. OPS CHECK OF FLAPS GOOD. FOR 2 FULL CYCLES IAW B767 AMM 27-11-44. NO FAULTS ON FSEU IAW FIM 27-51. AIRCRAFT RETURNED TO SERVICE.