What was found
(CAN) DURING A TIGHT LT 180 DEGREE TURN, CREW NOTICED A REDUCTION IN LT BRAKE EFFECTIVENESS, ACFT ACCELERATED THEN EMERGENCY PARK BRAKE WAS ACTIONED TO STOP THE ACFT, THEN CREW WAS PRESENTED WITH A BRAKE FAIL CAS MESSAGE AND THE HYD PRESSURE WAS INDICATING ZERO. THE HYDRAUIC RECOVERED AFTER THE ACFT WAS STOPPED. CMC DOWNLOAD CARRIED OUT. HYD SYSTEM CHECKED FOR QTY AND ACCUMULATORS PRECHARGED CHECKED. ACFT TAXIED AND BRAKE SYS FUNCTION CHECKED. UNABLE TO DUPLICATE FAULT BRAKE SYS FOUND SERVICEABLE. ACFT TAT 1808.3 TC 1609, DISCREPANCY: REF LOG 106317, BRAKE FAIL CAS MESSAGE, TECH SUPPORT REQUESTS FDR DOWNLOAD AND UPLOAD TO THEIR DATA SITE. DOWNLOADED CVDR FDR DATA DOWNLOADED AND UPLOADED TO MFG DATA SITE FOR THEIR REVIEW IAW AMM TASK 31-31-00-970-801-A. ACFT TAT 1808.9 TC 1610, DISCREPANCY: BRAKE INSPECTION REQUESTED BY MFG. LT BRAKE UNIT INSPECTED AND NO DEFECTS NOTED. ANTI-SKID GENERATOR INSPECTED AND NO DEFECTS NOTES. HYD PRESSURE SWITCH REPLACED AT EMBRAER REQUEST AND HYD SYSTEM OPS SERVICEABLE SWITCH, PN 3032015-001, SN ON: 7768-9-50 SN OFF: 764911-34, TSN: 479.2 HYD POWER PACK, PN 3032683-002, SN MX732711, TSN: 479.2 TSR: 14.0.