Oil Filters

Following a scheduled oil and filter change, the technician noted lower-than-normal oil pressure at idle. The new filter (p/n CH48110-1) was replaced and oil pressure indication was normal. Examination of the replaced filter noted some paint chips had been removed in the flange area. The submitter suspects that a paint chip could have contaminated the filter, causing it to go into bypass. These filters are packaged in cardboard boxes. There was no damage noted to the box containing the filter.

Editorial Staff

Tuesday, October 30, 2018 at 12:00 AM ET

Verified

Key Takeaways:

Multiple aircraft experienced critical oil system malfunctions, including low oil pressure or significant oil leaks, often immediately following oil filter replacement.
Many incidents involved new oil filters with suspected manufacturing defects, such as internal contamination (paint chips), damaged bypass valves, faulty threads, or insufficient mounting stud length.
One severe oil leak was caused by external mechanical interference, where a loose vacuum pump cooling shroud abraded and cracked the oil filter.