What was found
HYD 2 LO QTY MESSAGE FOLLOWED BY HYD 2 LO PRES MESSAGE. OCCURRED ON FINAL APPROACH AFTER WE LOWERED THE LANDING GEAR. PERFORMED A GO AROUND AND RAN QRH CHECKLIST. TOTAL LOSS OF HYD 2 QTY AND PRESSURE. BOTH WERE READING 0 % AND 0 PSI. NEVER COME BACK ON. EMERGENCY DECLARED. LANDED WITH NO INJURIES. CFR MET THEM ON THE RUNWAY AND THEY WERE TOWED TO THE GATE. REF NRWC 788-ORD-02382 FOR RAR OF LH MLG DOWNLOCK ACTUATOR RELEASE HOSE. #1 TIRE REQUIRES REPLACEMENT DUE TO HYDRUALIC FLUID CONTAMINATION. RAR REMOVED & REPLACED #1 TIRE IAW ERJ170 TASK CARD EA32-49-05-801. REF NRWC 788-ORD-02387 AMM 05-50-23, PERFORMED FUNCTIONAL TEST OF #2 EDP IAW AMM 29-11-01. OPS CHECK GOOD AND LEAK CHECK GOOD.