That old timer told me to use thermal paste on avionics connectors, I laughed

A guy who used to work on F-4s back in the 70s told me to put a tiny dab of thermal paste on Cannon plug pins before reassembly. I thought he was messing with me. Last month I had a bad corrosion issue on a pitot-static panel in a Cessna 172, tried his trick on the new pins. Zero issues since. Anyone else ever do weird stuff with dielectric compounds that goes against the book?

3 comments

3 Comments

baker.christopher3d ago

Dielectric grease works too, but thermal paste is better for pin contacts because it stays put under vibration. I've been doing it on older GA planes for years, especially on plugs near exhaust or anywhere moisture gets in. Just a tiny dab, don't slather it or you'll push it into the connector body and mess up the seal.

maxl933d ago

WOAH yeah I totally agree on the tiny dab thing. I learned that the HARD way on a Cessna 172 years ago. Put too much thermal paste on a pitot-static connector and it actually got between the pin and socket and gave me a wonky airspeed reading on takeoff. Now I use a toothpick to apply it, just a little smear on each pin before pushing it together. It's been rock solid on my plane's EGT probes ever since.

simon_carr3d ago

Question whether it's really that serious though. I mean, I get that a little dab of thermal paste might help on some connectors, but are we sure this isn't just one of those old-timer tricks that works because you're more careful when you're applying it? @baker.christopher I feel like if you're getting corrosion that bad on a Cessna 172, you've probably got a bigger issue like a bad seal or the plane lives in a swamp. I've seen guys do similar stuff with dielectric grease on spark plug boots and it just ends up making a mess when you go to pull the boots off later. Maybe it's fine for a few pins but I'd be nervous about it migrating somewhere it shouldn't and causing intermittent faults that are a pain to trace.