What was found
THE AUXILIARY INSTRUMENT VACUUM SYSTEM LINE PASSES CLOSE TO THE LT EXHAUST STACK. COMING OUT OF THE AFT SIDE OF THE IN-LINE FILTER IS A PLASTIC HOSE THAT CONNECTS THE FILTER TO THE HARD LINE. THIS HARD PLASTIC HOSE CANNOT TAKE THE HEAT FROM THE EXHAUST AND HAS A TENDENCY TO GET BRITTLE AND SPLIT OR BREAK. SOLUTION TO THIS PROBLEM WAS TO INSTALL A HIGH QUALITY, HIGH TEMPERATURE SILICONE HOSE IN PLACE OF THE CHEAPER FACTORY HOSE.