What was found
PRESSURIZATION COULD NOT KEEP CABIN BELOW 12000 FT ON CLIMBOUT WITH APU BLEED. F/A REPORTED SMOKE AND ODOR AT REAR OF CABIN JUST AFTER TURNBACK TO GJT. AT 16-17K AND ABOVE THE MAIN CABIN DOOR PRODUCED AN AIR LEAK. RETURNED TO GJT. REMOVED AND REPLACED RATE/MANUAL DUMP SWITCH. PRESSURE CHECKED AIRCRAFT IAW MM 21-30-00 USING TEST BENCH TO 4 PSID. CHECKED PRESSURIZATION ON GROUND WITH APU ONLY. CHECKED PRESSURIZATION ON GROUND WITH BOTH ENGINES IAW MM 21-30-00. OPS CHECKED ON GROUND GOOD. P/N OFF: MS27788-21P.