What was found
ON CLIMBOUT SAW RATE UP TO 3000' AND CABIN ALT TO 4000' THEN NORMAL. CYCLE REPEATED ONCE. ON ROLLOUT NOTICED DIFFERENCE .4 AND RATE TO 1500' FOR A FEW SEC. REMOVED FROM SERVICE. TEAR FOUND IN AFT BAG DOOR SEAL. REMOVED AFT BAG DOOR SEAL IAW Q400 AMM 52-31-26-000-801. INSTALLATION OF AFT BAG DOOR SEAL IAW AMM 52-31-26-400-801 STEPS 4A (13)-5C. SEAL OPS TEST GOOD. REPLACED CPCP IAW AMM 21-31-01-000-801 AND 21-31-01-400-801 OPERATIONAL TEST GOOD. C/W FUNCTIONAL TEST OF PRESSURIZATION CONTROL IAW AMM 21-31-00-720-801. FUNCTIONAL TEST GOOD. AIRCRAFT RETURNED TO SERVICE.