What was found
DEPARTING KDPA THE CREW NOTICED AND REPORTED DUAL PRESSURIZATION BLEED AIR LIGHTS HAD ILLUMINATED. THEY ELECTED TO RETURN TO DPA AND LANDED BACK THERE SAFELY. THIS WAS THE SECOND TIME THE SCREW EXPERIENCED THIS ISSUE. LAST LIGHT ISSUE RESET WITH 5 LEGS COMPLETED AFTERWARDS. ATI JET MAINTENANCE ARRIVED AT THE AIRCRAFT AND ENGINE RUNS/LEAK CHECKS WERE COMPLETED. A BLEED AIR MANIFOLD IN THE AFT BAGGAGE/TAIL SECTION AREA WAS FOUND WITH A LEAKING SLIP JOINT BLOWING AIR ONTO A TEMP SENSOR.