What was found
CABIN ALT WARNING AT FL350/RAN CHECKLIST, LT PACK ALREADY OFF FOR BLEED TRIP OFF. CABIN FOUND AUTO FAIL LIGHT & ALT LIGHT ON, ON CABIN PRESSURE MODULE. PERFORMED BITE TEST OF DCPC IAW FIM 21-31, TASK 801, & RESET CONTROLLER FOR RESET RECOVERABLE FAULTS IAW STEP B. (1) (C). EXISTING FAULTS SHOWED NO FAULTS, BUT FAULT HISTORY SHOWED MANUAL SWITCH & CAB ALT 10,000 FT. ON FLT LEG 00. FLT LEG 01 & 03 SHOWED LOW INFL/ HI LEAKG. PERFORMED GROUND TEST BITE PROCEDURE IAW FIM 21-31, TASK 801, SYS OK. DISPLAYED AT END OF TEST. PERFORMED PRESSURE SYS MANUAL MODE TEST IAW AMM. 21-31-00-710-801 TO CONFIRM OPS OF AFT OUTFLOW VALVE, TEST PASSED. PERFORMED CABIN PRESSURE LEAK TEST, RATE OF CLIMB STAYED ROSE TO .5 & LOWERED TO 0 WHILE DIFF PRESSURE STRUGGLED TO RISE PAST 1 PSI. FOUND BROKEN CLAMP ON APU DUCT IN HELL HOLE. R & R CLAMP IAW AMM 36-13-01-000-806 & PRESSURIZED AGAIN, NO HELP. PRESSURIZED ACFT AGAIN IAW AMM 05-51-91-790-801, FOUND MISSING BELLY DRAIN SEAL AT BS 727 AFT OF W/W ALSO FOUND LEAKING BELLY DRAIN SEALS NEAR E&E DOOR. R & R 4 DRAIN SEALS & REPLACED WIGH SERVICEABLE ONES IAW AMM 51-41-13-020-801. PERFORMED CABIN PRESSURE LEAK TEST IAW 05-51-91-790-801. CABIN DIFFERENTIAL PRESSURE WENT UP TO 4 PSI. NO LEAK FOUND ON REPLACED SEALS. OK TO CONTINUE.