1965 Cessna 172F Water in Tank

1965 Cessna 172F Water in Tank

Over the last 2 months I have made 3 flight into rain or mist for 15 minutes or less. All have been very light rain or mist but after landing I have sumped 1-2 inches of water from the tanks and once from the engine sump.  I suspected a fuel cap issue but the rubber gasket looks good and appears to have a good seal. If I pull up on the cap I can see a small gap in the rubber seal but don't think I could get the amount of water through the seal I am seeing.   Is there any other way I could be getting water into my tanks other then through the caps?  Any one else had this issue with some suggested fixes.  I am worried that if I get into a heavy rain or extended flight into rain I will start pulling water through the engine.


1 Posts
User info in posts
Only registered users or members can reply or post

Re: 1965 Cessna 172F Water in Tank

Hi Andy;

The fact that you can pull up on the cap and see a gap would indicate that the cap is not fitting tight enough.  The fuel caps on my Cessna's have always fit very tight. I would think this is the most likely source of the water.  The rubber gaskets do wear out, and the metal tangs that fit under the filler neck can get bent so that it doesn't fit as tight as it should.

It might also be possible that some water could enter through the vents.  On a 172 there is usually a vent in the cap opposite the under wing vent tube.  As the fuel level drops it will draw air through the vents.  From your post it sounds like you are checking right after flight, so it is unlikely the water is from condensation.  I am assuming that you are getting all the water out when you check the sumps, so it isn't carried over from the previous check.

Hope this helps.


186 Posts
User info in posts
Only registered users or members can reply or post

Board Info

Board Stats:
Total Topics:
Total Polls:
Total Posts:
User Info:
Total Users:
Newest User:
Members Online:
Guests Online:

There are no members online

Forum Legend:

 New Sticky