As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING PHASE CHECK, MAINTENANCE NEEDED TO PERFORM INFLATION TEST OF DE-ICING BOOT. THE MECHANIC CONNECTED A SHOP AIR SUPPLY REGULATOR TO THE BLEED HOSE, PN 946-37-74-101 AND NOTICED THAT THE HOSE WAS LEAKING. THERE WAS NO CHAFING OR ANY OTHER EVIDENCE ON THE FLEXIBLE HOSE SO THAT THE DEFECT CAN ONLY BE FOUND BY PRESSURIZING THE HOSE.