IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
78-00
March 2020
Page 291
IO-390-D Series Engine Maintenance Manual
78-00 - EXHAUST SYSTEM - INSPECTION
1.
Exhaust System Inspection
A.
Remove any components that interfere with this inspection.
B.
Examine the exhaust flange to exhaust port connections for a powdery white to light brown
or black residue indicating exhaust leakage.
C.
Replace any leaking gaskets (Figure 1).
CAUTION
EXHAUST LEAKS CAN CAUSE DAMAGE TO SPARK PLUGS,
IGNITION CABLES, AND THE CYLINDER HEAD. EXHAUST GAS
LEAKAGE BETWEEN THE EXHAUST FLANGE AND EXHAUST PORT
PAD CAN QUICKLY ERODE THE CYLINDER HEAD. IDENTIFY AND
CORRECT THE CAUSE OF ANY LEAKS. IF LEAKAGE IS FOUND, IT
COULD BE NECESSARY TO OR REPLACE THE CYLINDER PER
CHAPTER 72-30.
D.
Tighten any loose gasket flange assemblies in accordance with the torque values in the latest
revision of the
Service Table of Limits - SSP-1776.
E.
Examine exhaust manifolds for visible damage such as bulging, cracks, dents, residue and
overall general condition. Correct deficiencies in accordance with aircraft or exhaust
manufacturer’s procedures.
Figure 1
Exhaust Gasket
