What was found
(CAN) ON CLIMB OUT, THE CREW REPORTED A CARGO BTL LO CAUTION MESSAGE. THE QRH WAS FOLLOWED AND IT WAS DECIDED TO RETURN TO WHERE THE ACFT LANDED WITHOUT INCIDENT. MX FOUND A BROKEN DUCT COMING OFF THE LT PACK HEAT EXCHANGER THAT HAD CAUSED THE BOTTLE TO DISCHARGE. THE PACK WAS DEFERRED ALONG WITH THE CARGO FIRE SUPPRESSION SYS. THE CARGO BOTTLE WAS REPLACED ON MAR 25 AND THE BROKEN DUCT WAS REPLACED ON MAR 26. NO FURTHER DEFECTS NOTED. DUCT 601R95068-7, LEAKING PACK.