Leaking wing drain sump 68 M20F

[mikesalman]

Any advice on how to repair or replace the wing sump drain? It's on my right wing and does not appear to unscrew. My mechanic tried blowing air back into it hoping that would fix the problem, but it did not.

[AmigOne]

Never seen a wing sump that does not unscrew. I had my left wing drain sump replaced at the last annual and the mechanic didn't even drain the fuel tank.

Caruso wrote sometime back these useful comments:

"As you would guess, the drains are a simple spring loaded valve.

You can remove and clean them quite easily. They have a rubber seal, so don't over torque when replacing them.

You can also buy a new one if that makes you feel better

Be careful when working with fuel, it spreads everywhere and can be ignited.

The usual case of some junk stuck in the valve seat can sometimes be alleviated just by draining, open and close the valve many many times. It helps to have somebody available to pour the fuel back into the tank when this happens.

Look for what is causing the valve to stick open, sealant, rust and paint chips often are found in M20C sumps, (experience)....

This is an easy A&P fix if you are not comfortable with the work. It's not even Mooney specific."

[N601RX]

Any advice on how to repair or replace the wing sump drain? It's on my right wing and does not appear to unscrew. My mechanic tried blowing air back into it hoping that would fix the problem, but it did not.

Does the plane have bladders or wet tanks?

[Glenn]

I believe that the original quick drains were held in by two rivets.  An A&P should be able to replace this with the newer screw-in type.  If you ever have to replace it again, it will be much easier.

[yvesg]

You might want to look at this thread:

http://mooneyspace.com/topic/8979-always-have-a-fuel-drain-spare-or-plug/

In there I have a picture of a disassembled drain plug. There is a snap ring that holds it all together. The rubber ring dislodged from the post and I destroyed it while taking all this apart. I have sourced a compatible o-ring and fixed it. It is now my spare that I keep in the junk box in the luggage area... just in case the new one fails. However these ar worth only about $20.

Make sure you have a new one handy before the current one gets removed. Here is a picture of what it looked like last year before I got it replaced by my A&P. If yours look better... it should unscrew...

Yves

[danb35]

Some early Mooneys had fuel drains that were riveted in, as Glen notes.  SB M20-188A (http://www.mooney.com/images/pdfs/sb-pdf/m20_188.pdf) gives instructions on converting to screw-in valves.

[rockydoc]

Let me know what you wind up doing.  I've got the same problem in my B model which does not have the screw in type drains, meaning that Mooney SB M20-188A applies to me.  I don't relish having to make that complex a repair for a minor drip, but it appears there is no other recourse.

[mikesalman]

Does the plane have bladders or wet tanks?

Wet tanks.

[mikesalman]

Some early Mooneys had fuel drains that were riveted in, as Glen notes.  SB M20-188A (http://www.mooney.com/images/pdfs/sb-pdf/m20_188.pdf) gives instructions on converting to screw-in valves.

Thanks for the link. I will take it to my AP in the morning.

[carusoam]

Mike,

What year is your F?

For 65 and newer.... (based on my 65C experience)

Take a close look at what you have... The drain is a hex head, like a nut... A socket wrench with the appropriate size socket should fit.

Remember, it's upside down, so lefty loosey to make it come out...righty tighty to put it back. Pilot acceptable maintenance I believe...

It's better to be cautious when working near or with fuel. Empty the tank before removing the sump, is a good idea.

The B model is definitely different in this area, but expect C,D,E,F and G to have the unscrew type...

Best regards,

-a-

[danb35]

Replacing fuel drains is not on the preventative maintenance list, but I'm sure it gets done by the hangar fairies pretty frequently.

[mikesalman]

Mike,

What year is your F?

For 65 and newer.... (based on my 65C experience)

Take a close look at what you have... The drain is a hex head, like a nut... A socket wrench with the appropriate size socket should fit.

Remember, it's upside down, so lefty loosey to make it come out...righty tighty to put it back. Pilot acceptable maintenance I believe...

It's better to be cautious when working near or with fuel. Empty the tank before removing the sump, is a good idea.

The B model is definitely different in this area, but expect C,D,E,F and G to have the unscrew type...

Best regards,

-a-

It's a 1968 F. I will show the AP this message you never know you could be on to something.

[mikesalman]

$150.00 for the drain plug conversion kit from Laser. Ouch, I figured I would go for broke and ordered the cowl closure too. Lol

[Marauder]

You won't go absolutely broke until you go to have the cowl enclosure painted and realize your plane's paint is faded and you decide to have it painted, only to find the interior looks drab compared to the new paint and you need to have it redone, which you do, but find that your sorry looking panel needs an update that you update and it goes on and on and on...

[MARZ]

I've got one of each flavor so at some prior point the left wing was converted and the right remained stock.  About a two months ago mine started a very slow drip, I only noticed the blue ring on the cement below the sump, and a little bit of moisture on the sump itself.  My A&P says its not a real bad fix, just the pain of breaking the inspection covers.  The original drain gets drilled out, a nut base gets installed complete with tank sealant etc. 

 

My sump quit acting up, but I'll be doing the conversion at the next annual.

 

For the record, I did the enclosure, I lucked out with a good paint match and a lot of waxing

HOWEVER - that interior is looking a little shabby

[mikesalman]

I just purchased my 68F in late January this year and she came with new interior (3 years old) and new paint also 3 years old so hopefully it should be a easy match.