The Cessna 120-140 Association Forum

Anyone have any idea where they could come from? We changed the fuel selector to the new type. I couldn't think of any other possible source, unless the fuel truck had a problem.

atypicalguy wrote: ↑Wed Sep 23, 2026 4:44 pm Anyone have any idea where they could come from? We changed the fuel selector to the new type. I couldn't think of any other possible source, unless the fuel truck had a problem.

Personally I would doubt that the fuel truck has an issue, but instead the debris that you're seeing in the fuel strainer are more than likely as a result of you having the fuel selector changed whereby the fuel system has been opened up. Additionally, were any new aluminum lines or aluminum fittings added during the valve installation? If yes, there's a good possibility that's the cause, and eventually the situation should clear up.

If it were my aircraft, I would: (1) Monitor the fuel when using the strainer to see how much additional debris comes out. (2) Have the screen in the fuel gascolator located on the firewall inspected and cleaned a few times in order to check for the metal flakes.

If you don't mind, keep the site posted on your progress and findings. Just my 2 cents.

Did you find the flakes when cleaning the screen, or when draining the gascolator?

How much fuel have you run through it since you changed the valve?

Have you run more fuel through it since you discovered the problem? Did you find more flakes? Were they ferrous (magnetic) or not (aluminum)?

This is ultra rare for our aircraft. Follow John's (and Mike's) lead as to whether they are magnetic or not and we can probably help you track down the source.