1964 M20E engine fuel sump drip after flight

[Pilot boy]

Noticed a small fuel drip from the engine sump after flight the other day 1964 M20E.  If I leave the fuel selector off the drip stops but if I select a tank it drips a little.  I’ve read on here about an o ring opinion the valve that can get stuck or damaged.  I did pull the drain ring in the cockpit up harder and higher than normal a few days ago (I actually remember thinking that was a bit too much force... )so I wonder if I dislodged something.  Any thoughts, suggestions?  It is leaking I’d say 1/8 gallon over 24 hrs if I leave the fuel on a tank, one drip every 30 sec to one minute.

 

 

 

 

[Rjfanjet]

Had an issue like this. I was losing 1/2 gallon a day when selected to the left tank. Got the fuel selector overhaul kit from LASAR. Took my mechanic and myself an hour to clean the selector and replace all the O rings. Problem solved. No leaks for 2 weeks.

[carusoam]

The cockpit fuel drain is a bit funky...

The drain valve has a rubber tip glued in place...

People have learned that you can activate the drain from under the plane like any other fuel sump...

But the cost of knocking off the piece of rubber makes it a bit of a hassle....

 

If needed find the service bulletin or MM that has the proper glue and rubber bit to go with that...

 

Its possible a piece of junk got stuck in side it, try and get it flushed out... fuel has to get past two screens before it gets that far...

 

My M20C used to store rust bits there... the rust came from the fuel necks for the caps....

 

PP thoughts only...

Best regards,

-a-