What was found
AIRCRAFT WAS GROUNDED: WHILE CLIMBING TO FL360 CABIN ALTITUDE /DIFFERENTIAL PRESSURE PASSING 32000 WAS 8.95 PSI AND CABIN ALTITUDE WAS 3900 FEET. REQUESTED DESCENT AND LOST PRESSURIZATION RAPIDLY UPON COMMENCING DESCENT. EMERGENCY DECLARED; FIGHT RETURNED TO MIA LANDING SAFELY. MAINTENANCE REPLACED #1 ENGINE BLEED AIR REGULATOR PER AMM 36-11-03 (AALA202305162596); REPLACED OUTFLOW VALVE PER AMM 21-31-00 (AALA202305167395); REPAIRED BROKEN WIRE W6102 AT CONNECTOR D10732 PER WDM 21-32-22 (AALA202305169498); REPLACED BOTH POSITIVE PRESSURE RELIEF VALVES PER AMM 21-32-01 (AALA202305163620, AALA202305162546); REPLACED CABIN PRESSURE CONTROLLER #1 AND CABIN PRESSURE CONTROLLER #2 PER AMM 21-31-00 (AALA202305161692, AALA202305169725). ACCOMPLISHED SATISFACTORY OPERATIONAL AND LEAK CHECKS.