What was found
DFW - CREW REPORTED TAIL COMPARTMENT TEMPERATURE HIGH LIGHT ILLUMINATED DURING CLIMBOUT. FOLLOWED QRH PROCEDURE AND LIGHT EXTINGUISHED AFTER FOUR SECONDS. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND DUCT PERI SEALS TO PRIMARY HEAT EXCHANGER LEAKING AND PNEAMATIC AIR CONTROL THERMOSTAT LEAKING. REPLACED PERI SEALS, THERMOSTAT AND SECURED CLAMPS FROM AIR CYCLE MACHINE TO HEAT EXCHANGER. SYSTEM GROUND CHECK NORMAL OPERATION.