Lycoming IO-390-D Series Maintenance Manual page 101

IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual
The visual inspection procedure is slightly different for oil filter elements and screens:
Visual inspection for oil filter element:
Remove the oil filter element from the oil filter
canister.
Drain all fluid oil through a strainer cloth or
paper to remove oil from the oil filter as much as
possible to enable better visibility of the metallic
particles and prevent loss of metallic particles.
Since quantity matters, try not to lose particles.
Loss of metallic particles can compromise the
integrity of this inspection.
Open up and unravel the oil filter element on a
clean sheet of white paper or cloth.
Use bright light illumination to look at the panels
and folds on the filter element for any shiny
metallic solids.
Look for any copper-colored metallic particles.
Estimate the size and number of metallic
particles.
Typically, small metallic particles, chips, and chunks on either the oil filter element or oil pressure
screen or oil suction screen during the first oil change of a new, rebuilt, or overhauled engine, are
acceptable. After an initial break-in period, metal content is likely to decrease rapidly to a level that
remains essentially constant.
However, on subsequent oil changes, an increased quantity of chunks, chips, and/or small metal
particles in the oil can be evidence of engine part wear. This wear can increase over a period of time
until premature loss of form, fit, or function occurs.
NOTICE: If the engine has been operated in dust, sand storms, volcanic ash, wildfires, etc. more
particulates could be found.
Table 2 identifies field tests and guidelines for identifying types of metals as well as possible sources
and the next step in the process.
Table 3 identifies the size and amount of material and the recommended corrective action.
Table 4 identifies specific corrective action for the various findings.
The type of material (Table 2), regardless of quantity, and/or the quantity and size of metallic
particles (Table 3) can help determine the corrective action (Table 4) to be taken.
© 2020 Avco Corporation. All Rights Reserved
March 2020
Visual inspection for oil pressure screen and
oil suction screen:
Drain all fluid oil through a strainer cloth or
paper to remove oil from either the oil pressure
screen or oil suction screen as much as possible
to enable better visibility of the metallic particles
and prevent loss of metallic particles. Since
quantity matters, try not to lose particles. Loss of
metallic particles can compromise the integrity
of this inspection.
Scrape all of the remaining metallic particles
onto a clean teaspoon, paper or cloth.
Look at metallic particles for any shiny metallic
solids.
Look for any copper-colored metallic particles.
Use non-metallic tweezers or a pick to sort
chunks, chips, and particles that look different.
Estimate the size and number of metallic
particles.
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