What was found
RTB - AFTER TAKEOFF. SYS 4 HYDS FAILED. FLUID LEVEL 0. A/C WOULD NOT PRESSURIZE. DURING FUEL DUMP FOR RETURN. SYS 1 LOST ALL REMAINING FLUID. SYS 2 HYD FLUID LEVEL DECREASING (DID NOT GO TO 0). ON LANDING. FOUND LH MLG WHEELS 7 & 8 BLOWN. R/R #7 & #8 IAW AMM 32-45-01 REV 110. R/R #7 & #8 PER AMM 32-45-01 DUE TO POSSIBLE LDG FAILURE. R/R #7 & #8 BRAKE ASSY IAW AMM 32-41-15 DUE TO HIGH ENERGY STOP / OVERHEAT. PERFORMED REPAIR IAW AMM 20-11-05 ON LH MLG W/W DAMAGED HYD LINE. PRESSURE & LEAK CHECK GOOD. R/R LH MLG DAMAGED HYD LINE IAW AMM 20-11-05, LEAK CHECK GOOD. R/R LH SEQUENCE VALVE IAW AMM 32-33-02. LEAK CHECK GOOD. NO DEFECTS NOTED. R/R BOTH CASE DRAIN ELEMENTS ON SYS 1 & 4 IAW AMM 29-11-18.