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Fuel weep inside of cabin from the right wing


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when my right wing is near full of fuel, or if it gets cold outside I get a fuel odor in my cabin....while avionics crew is pulling wires I took pictures of my fuel pick-up fitting, and fuel level sender mount are both leaking.  I was wondering if the screws could be tightened...are the nuts attached to a flange on the other side...am I going to have to take the tank apart and redo epoxy from the inside of the tank to get it to stop leaking?

851146849_2019-03-0814_27_15.thumb.jpg.3d5a00eccfe69a92ee759bd73b5421d2.jpgPicture need rotate 902105518151_2019-03-0814_28_00.thumb.jpg.63ab6698892920aa7e57bb89ae50bad5.jpgpicture is upside down

Edited by larrynimmo
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It’s interesting that someone decided to smear Buna-N (the red film) on the inside. That’s not a sealer (it’s put on as a top coat over the sealer) but it’s also unlikely to be part of your current problem. You could try making sure the screws are tight but I doubt it will help much, with the caution that you might make it worse. Both the sender and the pickup seem to be leaking from what I can see, right?

 

As the resting pressure of the fuel increases with fuller tanks, you get more weeping. The sealant becomes less pliable over time and temperatures affects it more, and the gaskets on both units degrade.

 

This looks like an relative easy fix if you are only leaking past the gaskets. Both units can be manipulated through just the top aft fuel panel. Here’s a pic of what the inside looks like if you e never seen it. We do fuel tank reseals regularly, I see this often.

 

2b812a5f1b2316d814d917482bb9b6d3.jpg

 

 

DVA

 

 

Sent from my iPhone using Tapatalk

 

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I had the same "fragrance" in my '84 J and tightening the screws on the fuel pickup did the trick for me, although you look like both the pickup and sender need tightening on yours. I was worried I needed to replace the gasket, and then found out it is a $60 part!

Once you get them all tightened, clean off the residue from the leaks and watch it for a few days. It should stay clean. If not, then it is time to get your local mechanic involved. Good luck!

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when my right wing is near full of fuel, or if it gets cold outside I get a fuel odor in my cabin....while avionics crew is pulling wires I took pictures of my fuel pick-up fitting, and fuel level sender mount are both leaking.  I was wondering if the screws could be tightened...are the nuts attached to a flange on the other side...am I going to have to take the tank apart and redo epoxy from the inside of the tank to get it to stop leaking?

851146849_2019-03-0814_27_15.thumb.jpg.3d5a00eccfe69a92ee759bd73b5421d2.jpgPicture need rotate 902105518151_2019-03-0814_28_00.thumb.jpg.63ab6698892920aa7e57bb89ae50bad5.jpgpicture is upside down

 

You have a cork gasket sitting underneath. Tightening a little may stop the leak.

 

6dc4a1ac408ba641e483c64bf4f66fe4.jpg

 

Bladder system.

 

 

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I had a similar issue and (carefully) tightening the screws solved the problem.   I've since installed new senders, etc., so that was the bigger cure.  ;)

1 minute ago, Bryan said:

Those of you that have installed CiES senders, do they come with new gaskets?

ordered the senders and want to be prepared for the install to have everything needed.

I believe new gaskets are included, or at least I didn't get charged for gaskets when mine was put in.  ;)

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Those of you that have installed CiES senders, do they come with new gaskets?
ordered the senders and want to be prepared for the install to have everything needed.


Yes. Old and new senders next to each other

ccefa6d9e439101d81736d5c313484e7.jpg


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I think there's a torque spec on those perimeter screws - Clarence will be along shortly to confirm - you want to squeeze that gasket tight enough and uniformly. Cork is probably more sensitive to proper installation. There's a rubber gasket alternative that's thicker an probably more forgiving and longer lasting. @M20Doc

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21 hours ago, larrynimmo said:

It’s leaking pretty good from one of the screws for the fuel pixup...looking to see if I can fix with taking out tank access covers...just one screw leaking

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C9CAC4BA-4ED2-482B-8B3A-776511B57DA7.jpeg

It's always the one under the pickup tube because it is a bear to get tightened and torqued properly.

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On 3/9/2019 at 2:39 PM, larrynimmo said:

It’s leaking pretty good from one of the screws for the fuel pixup...looking to see if I can fix with taking out tank access covers...just one screw leaking

E661569E-20B3-4D4F-84D8-E567859E775B.jpeg

C9CAC4BA-4ED2-482B-8B3A-776511B57DA7.jpeg

Remove the screw and replace it with an AN3 bolt, much easier to torque with a crows foot wrench.  Transfer the washer to the bolt.

Clarence

Edited by M20Doc
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I re did one of my senders three times and it still leaked, so I put a light coating of tank sealant on the sender, the airframe and both sides of the gasket. It didn't leak a single molecule of fuel after that. I had to remove it about a year later and was thinking it would be a horror story getting it apart, but it wasn't that hard and cleaning it up for a reseal was no big deal. 

I know it isn't by the book, but it works.

BTW, it wouldn't reseal because too many ham fisted mechanics were in there before I bought the plane!

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36 minutes ago, N201MKTurbo said:

I re did one of my senders three times and it still leaked, so I put a light coating of tank sealant on the sender, the airframe and both sides of the gasket. It didn't leak a single molecule of fuel after that. I had to remove it about a year later and was thinking it would be a horror story getting it apart, but it wasn't that hard and cleaning it up for a reseal was no big deal. 

I know it isn't by the book, but it works.

BTW, it wouldn't reseal because too many ham fisted mechanics were in there before I bought the plane!

Good job! Who would have figured?  Fuel sealant actually seals fuel.

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  • 2 weeks later...

Completion Report....

I completely removed the bottom fuel pick-up tube cleaned up the whole area with acetone and it cleaned up nicely.., installed a new $62 mooney gasket, put non hardening Permatex on the threads, and that was fixed.  As for the fuel gauge I couldn't get it to pop loose (must be glued in place) removed old screw, installed new screws with the nylon crush bushing barrels, new screws and a light coating of non hardening Permatex and torqued everything.  I only went to 15 inch pounds because it felt pretty tight at that.  I also, took the opportunity to replace the 40 year old fuel hose, and installed a new quick drain for the tank.  FYI if you order a fuel sender gasket from Mooney they are now sending a rubber one rather than the cork ones...it cost $28, but I ended up not using it.  The plastic barrel bushings only cost $.50 each.  Put 25 gallons in the tank...and no leak what-so-ever.  YEAH!

My A&P mechanic told me that you don't need sealant on the screws (even though we did it) because when you use a new gasket the crushing force of the compression is supposed to seal the screw threads so that nothing can pass through.

IMG_3696.JPG

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1 hour ago, larrynimmo said:

Completion Report....

I completely removed the bottom fuel pick-up tube cleaned up the whole area with acetone and it cleaned up nicely.., installed a new $62 mooney gasket, put non hardening Permatex on the threads, and that was fixed.  As for the fuel gauge I couldn't get it to pop loose (must be glued in place) removed old screw, installed new screws with the nylon crush bushing barrels, new screws and a light coating of non hardening Permatex and torqued everything.  I only went to 15 inch pounds because it felt pretty tight at that.  I also, took the opportunity to replace the 40 year old fuel hose, and installed a new quick drain for the tank.  FYI if you order a fuel sender gasket from Mooney they are now sending a rubber one rather than the cork ones...it cost $28, but I ended up not using it.  The plastic barrel bushings only cost $.50 each.  Put 25 gallons in the tank...and no leak what-so-ever.  YEAH!

My A&P mechanic told me that you don't need sealant on the screws (even though we did it) because when you use a new gasket the crushing force of the compression is supposed to seal the screw threads so that nothing can pass through.

IMG_3696.JPG

Thanks for your report.  This will help a lot of folks in the future.

 Versachem Prime Seal Type 3 Aviation also does the trick on these leaky screws.  We replaced a sender gasket last year, and I had to use this to stop seepage. Re-torqueing alone was not sufficient.  

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On 3/8/2019 at 8:07 PM, M20Doc said:

Here is your torque value.  Some Acetone on a rag will clean up the old fuel dye.

Clarence

 

218B84C2-D94C-4A4D-9CE4-0F6129BED70D.jpeg

I don’t trust this instruction....first off senders only have 5 holes.  When I tightened mine, I felt very uncomfortable torquing to 15 inch pounds....and I do believe I made the right decision not to go further....The screws for this are a 6/32...look at the torching guide in the mooney service manual.  Size 6 isn’t listed, but use size 8 as a guide

93A34CE8-3A44-4713-B98B-52B52C242F20.png

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I’ve never seen a fuel quantity transmitter held on with 6-32 screws.  They have always been 10-32 screws or bolts.  

Clarence

E1314F2A-FF57-4B9B-B12E-1AF253BCD1C2.jpeg

Edited by M20Doc
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