Old timer told me to stop using dielectric grease on cannon plugs, he was right

I had a senior tech named Bob who worked on F-16s back in the 80s tell me that dielectric grease does more harm than good on cannon plugs in dry cabin environments. He said if the plug is properly sealed and torqued, you don't need it and it just attracts dirt over time. I ignored him for about 6 months because every other guy I worked with swore by it. Then I pulled a plug on a King Air that had a thick layer of crusty grease mixed with dust and moisture inside. Three pins were starting to corrode underneath all that gunk. Bob took one look and said "told you so." I cleaned everything out with contact cleaner and a stiff brush, put it back dry, and that plug has been fine for the last two years. Has anyone else run into problems with grease causing more issues than it solves?

2 comments

2 Comments

vera_roberts18d ago

@luna_wells57 have you ever seen corrosion form under that gunk in a dry cabin or do you just think it's pointless?

luna_wells5718d ago

I read something similar from an old avionics guy on another forum. He said dielectric grease is basically a band-aid for bad connections, and if the pins are clean and tight you don't need it. I started skipping it on our cabin plugs about a year ago after finding a goopy mess inside one of the entertainment system connectors. Haven't had a single issue since.