4-123. HEATER EXHAUST PIPE REPLACEMENT (M373A2D AND M373A5) (Con't).
Remove six bolts (5) and Iockwashers (6) securing upper exhaust pipe (4 or 27) and gasket (7) to lower exhaust
pipe (8). Remove upper exhaust pipe and gasket. Discard gasket and Iockwashers.
Working inside semitrailer, disconnect union (17) connecting exhaust pipe (16) to heater.
Remove six bolts (15) and Iockwashers (14) securing exhaust pipe (16) and gasket (13) to mounted pipe flange
(12). Remove exhaust pipe and gasket. Discard gasket and Iockwashers.
Perform steps 8 through 10 only if parts still mounted to semitrailer wall are damaged.
Remove four rivets (1) [screws (18) on M373A5] securing cover plate (1 O) to semitrailer front wall. Remove cover
plate, gasket (1 1), and pipe flange (12) as a unit. Separate parts and discard gasket and rivets.