Induction System Maintenance; Induction System Inspection; Intake Pipe Replacement - Lycoming IO-390-D Series Maintenance Manual

IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual

1. Induction System Inspection

A. Examine the air intake pipes (Figure 1) for leaks, security.
B. Examine the air filter for damage.
C. Service in accordance with the manufacturer's service procedure. Evidence of dust or other
solid material in the ducts is indicative of inadequate air filter care or a damaged air filter.
CAUTION
D. If there is dust (other than volcanic ash) or other solid material in the air ducts, remove the
dust and contaminant, examine the air filter and replace the air filter if necessary. Identify the
cause of the problem per the aircraft Original Equipment Manufacturer (OEM) procedure.
E. Identify and correct the cause of the problem per the aircraft manufacturer's instructions.

2. Intake Pipe Replacement

NOTICE: Each engine cylinder has a corresponding intake pipe of a different part number. Be
sure to replace the intake pipe with the replacement intake pipe of the correct part
number that corresponds to the engine cylinder number (Figure 1).
A. Intake Pipe Removal
(1) Remove the two bolts, lock washers, and washers from the intake pipe flange at the
engine cylinder (Figure 1). Discard the lock washers.
(2) Remove the gasket from the intake pipe, discard the gasket.
(3) If the intake pipe is not to be replaced, attach a label to the intake pipe that identifies the
corresponding engine cylinder number for reference on assembly.
(4) Pull the intake pipe and ring seal from the oil sump. Discard the ring seal.
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March 2020

72-80 - INDUCTION SYSTEM MAINTENANCE

Intake Pipes and Attaching Parts
TAKE PRECAUTIONS IN THE NEXT STEP, IF VOLCANIC ASH IS
SUSPECTED ON THE ENGINE, DO NOT TOUCH IT WITH BARE
HANDS OR GET IT IN YOUR EYES. THE VOLCANIC ASH CAN
CONTAIN ACIDIC COMPOUNDS WHICH MUST NOT BE INHALED
OR TOUCHED SINCE IT CAN CAUSE INJURY. DO NOT USE WATER
TO RINSE IT OFF. WEAR PERSONAL PROTECTIVE EQUIPMENT.
REFER TO THE SECTION "VOLCANIC ASH/PARTICULATE
CONTAMINATION" IN CHAPTER 05-50.
Figure 1
72-80
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