What was found
INADVERTENT ACTIVATION OF EMERGENCY AIR FLOW AT 9000 FT. TROUBLESHOOTING, INSPECTION OF PRESSURIZATION SYSTEM COMPONENTS, GROUND AND SUBSEQUENT FLIGHT PRESSURIZATION CHECKS PROVED NO NOTED DEFECTS. DURING OPERATIONAL CHECK/TESTS, FOUND PRESSURE REGULATORS FOR PRESSURIZATION AND TEMPERATURE CONTRL TO BE MARGINAL IN OPERATIONAL PRESSURE. REMOVED AND REPLACED BOTH LEFT AND RIGHT SERVO AIR PRESSURE REGULATORS IAW LEAR 31 MM 21-30-08, PAGE 201. FUNCTIONALLY CHECKED BOTH REGULATORS INDIVIDUALLY TO ENSURE THEY REGULATE AT 15 SPI. SATISFACTORILY COMPLETED AN OPERATIONAL CHECK OF PRESSURIZATION SYSTEM IAW LEAR 31 MM 21-30-00 PAGE 209. (M)