Mike Noel wrote:
I have seen this discussed before, but couldn't come up with any hits on
Google. The sump drains on one wing an at the engine are running very
slowly, so I suspect they need to be cleaned. Also, the one that does drain
well continued to drip after I had drained a fuel sample until I had jiggled
it around for a bit. Interestingly (ominously?), the one that does drain
well gave me a few dark flecks. What is the best way to clean up these
drains, or would it be best to replace them?

Mike,

My mechanic just replaced both main tank drains on our 172 after I
noticed the very same symptoms on one of the drains. We technically
only needed to replace the right side drain, but I figured I'd do both
because they're reasonably priced and I wanted to change them to a
"flush" type like that used on the new 172. They now flow like Niagra
Falls. 8^)

He used the "thumb" method to replace the drains rather than draining
the tanks. What's the "thumb" method you ask? Unscrew the drain. When
it comes out, use your thumb to close over the hole, then release, then
close it up again. Lather, rinse, repeat a few more times to make sure
you remove any gunk that might be hanging out in the bottom of the tank.
When done, screw the new drain in, and safety wire accordingly.

We "spilled" about a quart or so into a basin I strategically positioned
beneath the drain during the procedure to ensure we caught it all. Once
we verified the gas in the basin was clean, we poured it into the tug.
Nothing wasted.

HTH,

-Doug

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Doug Vetter, CFIMEIA

http://www.dvcfi.com
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