What was found
BRAKE DIFF TEMP ALERT CLIMBOUT. TEMPS ON LT MAIN TRUCK WERE : NR1-72, NR 2-387, NR 3-95, NR 4-127 DEGREES. NR 2 BRAKE TEMP WAS CONTINUING TO INCREASE. GEAR EXTENDED TO EXPEDITE COOLING. WHEN TEMP DECREASED TO 225, GEAR WAS RETRACTED. INSPECTED NR 2 BRAKE, FOUND BRAKE DISK BROKEN AND VERY HARD TO SPIN WITH AXLE ON JACK. R & R NR 2 BRAKE ASSY IAW AMM 32-43-20-4. OPS CHECK SATISFACTORY. ACFT OK FOR SERVICE. PREMATURE REMOVAL/INSTALLATION OFF MFG 2609472-4, POS 2 SRL B2857, TAG 3758C4 ON MFG 2609472-4 SRL B0591, TAG 44218B INSPECTED NR 2 BRAKE, FOUND BRAKE DISK BROKEN AND VERY HARD TO SPIN WITH AXLE ON JACK. R & R NR2 BRAKE ASSY IAW AMM 32-43-20-4. OPS CHECK SATISFACTORY. ACFT OK FOR SERVICE.