Lots of water in tank 67C

[chriscalandro]

I'm a bit lost on this one.  During the Florida winter I was getting quite a bit of water in one of my tanks.  I changed O-rings, and it appeared that solved most of the issue.  There was a while in Florida where it rained pretty heavily every single day.  It's been a while and it's been more dry here, but I have more water now than I have ever had.

 

Today I pulled 3 entire sump tester-s full of water from the left side tank.  The tanks aren't leaking, there is no fuel leakage on the top, so I don't think it's coming through the panels.  I removed the gas cap and filled the top with water and it doesn't leak through the smaller inner O-ring.  I did notice the cap was slightly lose, so I tightened the castle nut as tight as I could get it and still be able to put the cap back on.

 

What else could it be!?  It's a LOT of a water.

[Marauder]

I'm a bit lost on this one.  During the Florida winter I was getting quite a bit of water in one of my tanks.  I changed O-rings, and it appeared that solved most of the issue.  There was a while in Florida where it rained pretty heavily every single day.  It's been a while and it's been more dry here, but I have more water now than I have ever had.
 
Today I pulled 3 entire sump tester-s full of water from the left side tank.  The tanks aren't leaking, there is no fuel leakage on the top, so I don't think it's coming through the panels.  I removed the gas cap and filled the top with water and it doesn't leak through the smaller inner O-ring.  I did notice the cap was slightly lose, so I tightened the castle nut as tight as I could get it and still be able to put the cap back on.
 
What else could it be!?  It's a LOT of a water.

That much water has to be coming through the cap during heavy rain. Try putting Glad Press and Seal over the cap area while it is parked and see if water keeps coming in.

You only have 4 potential entry methods if the tanks are not leaking: 1) the cap, 2) the vent, 3) condensation and 4) accidental or on purpose water introduction.


Sent from my iPad using Tapatalk Pro

[carusoam]

Time to update you ship’s data in your avatar area, Chris...

 

A slightly loose cap is capable of allowing quarts of rainwater into the tank...  An amazing amount of rain water is collected by the wing and passed to the cap before heading for the ground...

Really important... do you see any rust particles in the sumped fuel..? Tiny black specks...

If your four o-rings are new, and your cap is tightly sealed, and you are still getting quarts of water in the fuel tank... this is a different challenge...

Have you had the plane long enough to get through an annual inspection yet?

Mooneys built in the mid 60’s didn’t use stainless steel for the fuel neck... the forming weakened the area where it is mounted in the wing... the back side of this part rusts quite easily over the decades...

Best regards,

-a-

[chriscalandro]

There have been some pretty strong temperature changes around here, and with the humidity my first thought was condensation, but it's a lot.  I like the plastic wrap idea.  I'm going to try that.

No particles.  

[carusoam]

Chris...

you need to get onto a fix... not trying plastic wrap...

You have proven to yourself you have a water leak.

Get onto the fix... 

 

Prove to yourself... you have the right...

• orings... my M20C came with the wrong Orings that were sensitive 100LL and swelled... then leaked...
• hardware... what part number is your fuel cap... my M20C came with off spec plastic fuel caps that were UV sensitive and failed... then leaked...
• Set-up procedure... the maintenance manual has the procedure to properly make the right fuel caps impervious to water... every annual somebody takes the risk of undoing what was properly set up the year before...
• Inspect your fuel neck... some were made out of mild steel... if you don’t have shiny stainless parts... you have a high risk of the neck getting a hole in it... and passing quarts of water through a nearly invisible crack... My M20C did this as well... it took a decade of increasing risk for me to understand how big the challenge that I had was...

Being parked outside isn’t much fun... but having all the right stuff together makes it much safer...

Throw on the plastic wrap for additional protection, a Plan B... Or added protection to keep a few drops from falling in the tank when you open the cap for inspection...

Been there, done that, don’t want anyone I know to have to go through that...

Best regards,

-a-

[chriscalandro]

The first step is to determine if it's coming from outside or forming on the inside as condensation.  The plastic wrap will answer that question and I can move on from there.

 

They are the correct caps and they are the correct O-rings.  They were changed about 2 months ago.  The caps were adjusted today but I'm not convinced that was the problem.  

 

I did look at the filler neck.  While a little dirty, it cleaned up and I'm sure that isn't a problem.

[Prior owner]

You can take a length of hose and place it over the vent tube on the bottom of the wing....

Turn the fuel selector to “off”,  splash the fuel cap with a Little dish soap/water solution, and blow into the vent line. Look for bubbles at the fuel cap.

Edited November 24, 2019 by PilotCoyote

[carusoam]

Don’t wait for rain... to test your theory...

There are other ways to test the water tightness of the cap... Some that don’t involve risking getting water in the tank again...

 

The fuel neck is stainless or it isn’t... the non stainless isn’t shiny, and may have paint left on it, along with some sealant from the early days....

So...

If... you have the...

• right fuel cap
• the right seals
• installed using the right procedure
• installed into formed SS sheet metal parts...

Then... you don’t have a leak...

Else... you would have to define how that much water entered the tank’s vent...

 

(Fortran anyone?)

What you have described cannot possibly be condensation...  thinking that much water entered your tanks in an ordinary way will keep you from being focussed on what ever your real challenge is...

Stay focussed my friend... 

Best regards,

-a-

 

[EricJ]

What kind of o-rings did you use?     The non-fluorosilicone rings can fail somewhat quickly in the right conditions, like a lot of heat cycles.

Otherwise it only takes once not registering or locking the cap properly to get a bunch of water in there from a storm.

[chriscalandro]

 

I used these -

05-00107 MS29513-010 FUEL RESIST O-RING MS29513-338 MS29513-338 O-RING   I agree that it's probably too much water for ONLY condensation to be the problem (stupid Florida) I think a part of it might have been the cap being a little lose.  It needs to be washed, so I'm going to plastic wrap the cap, wash it, and see what happens. Then I'll remove the plastic, spray it down again, and see again, what happens.   I believe Eric might be on to something as well, and maybe those O-rings have already failed.  I came from Arizona and inside a hanger where it was never an issue to outside in Florida.  Again, I had this issue before (not as bad) and the new o-rings seemed to have solved it, but here we are again.  I would like to believe those o-rings would have a better life span than 2 months, even if they are garbage o-rings....

Edited November 24, 2019 by chriscalandro

[carusoam]

2 hours ago, chriscalandro said:

I did notice the cap was slightly loose,

At the moment you notice this... you have found the leak.

The sensitivity for the caps to be too tight to close, and too loose keep water out is about one turn on the nut...

This is why an ordinary mechanic is so challenged to get this right... where a Mooney mechanic has seen this often in the course of a year...

it’s not an exact quote... I added an extra o...

Best regards,

-a-

[chriscalandro]

It’s much less than that probably closer to a quarter turn, and it seemed like a pretty common sense thing. I don’t think adjusting a fuel cap requires a Mooney mechanic. I did it myself and I’ve never messed with it before. Pretty simple stuff. 

[Hank]

Also, make sufe when you put the cap on that it is straight and level, not slightly crooked. 

[chriscalandro]

If it’s properly tightened it should not be able to go on crooked, only straight as you will not be able to turn the actuator otherwise. 

[carusoam]

15 hours ago, chriscalandro said:

It’s much less than that probably closer to a quarter turn, and it seemed like a pretty common sense thing. I don’t think adjusting a fuel cap requires a Mooney mechanic. I did it myself and I’ve never messed with it before. Pretty simple stuff. 

Chris,

one turn... one facet... one minimum change...

I can try to be more specific if you like... 

It takes someone to care enough to do the job right...

 

Now....

Ordinary mechanic’s do care...

Mooney mechanic’s aren’t inherently special...

And yes, you probably care enough to do it correctly, and your hangar fairly probably does the book work...

But...  why was it loose in the first place?

Fuel caps don’t typically loosen up over time....

If the previous hangar fairy or mechanic put a note in the logs... you might get a hint of why and how long it has been out of adjustment...

 

It has been raining out for days this week...

Lets say you go out to the plane and see water on top of the fuel cap... this is a hint that the cap is sealed...

If there is no water on top... it has either dried up, or it went inside the tank...

If the cap is still wet, but no pool of water... this is a discouraging sign... the water didn’t dry up.

To confirm the test... put the small amount of water back on top... 

 

I’m not a fan of using actual water on the tank for testing... but the plane does go outside in the rain...   better to prove it in real world conditions... then to wait for ideal conditions to be present...

 

If small amounts of water go in the tank... and don’t come out... this is a different challenge...

You want to know where the sump drain is compared to the lowest corner of the tank...

How is that?

 

PP thoughts only, not a mechanic...

Best regards,

-a-

[carusoam]

17 hours ago, chriscalandro said:

my first thought was condensation, but it's a lot. 

 

This thought goes away for two reasons...

1) As you say... it’s a lot... tanks would need to be kept near empty to allow a lot of moist warm air in, then have the temps drop significantly to get a few drops...

2) It is in one tank, and not backed up by the same thing going on in the other, near identical tank...

 

The third observation is probably starting to make sense....

3) It happens each time it rains... 

 

Best regards,

-a-

[HRM]

17 hours ago, chriscalandro said:

There have been some pretty strong temperature changes around here, and with the humidity my first thought was condensation, but it's a lot.  I like the plastic wrap idea.  I'm going to try that.

No particles.  

I have a giganto roll of blue painter's tape (I think it is 2" wide) and I just tape over the fuel caps if I have to park my E outside. I doubt that condensation is creating that much water.

[Gagarin]

Most likely is leaking through the fuel cap adapter ring perimeter that is riveted to the wing. Best way to check this out is by blowing air into the tank vent (by mouth no more than 5 psi) and checking for bubbles at the filler cap using spray soap. It will point exactly to the leak source. If it show bubbles apply tank sealant to the adapter ring rivets.

[chriscalandro]

Today first thing I sumped the tanks and found a small amount of water in the suspect tank. I filled the cap indentation with water, sat and waited and looked like it had evaporated. Repeated 3 times. Sumped again, no water. Rocked it around a bit, sumped again, no water. 
 

with as much water as I found I’m hesitant to add contaminants other than water to the mix. At least I know I can get the water out. 

[HRM]

So to summarize, only one side has this issue and you have concluded that it isn’t the fuel cap.

 

[Sabremech]

18 hours ago, carusoam said:

At the moment you notice this... you have found the leak.

The sensitivity for the caps to be too tight to close, and too loose keep water out is about one turn on the nut...

This is why an ordinary mechanic is so challenged to get this right... where a Mooney mechanic has seen this often in the course of a year...

it’s not an exact quote... I added an extra o...

Best regards,

-a-

A fuel cap is too difficult for an ordinary mechanic? Really? This myth that a Mooney requires a special mechanic is getting very old. 

[chriscalandro]

31 minutes ago, HRM said:

So to summarize, only one side has this issue and you have concluded that it isn’t the fuel cap.

 

Yeah, seems to be that way. I also fill to the top every time and there is no sign of a leak either through the panels or any rivets. 

[Guest]

Don’t pressurize your tanks to 5 PSI, the correct value per SB M20-229A is 0.5 PSI

Clarence

[DonMuncy]

21 hours ago, chriscalandro said:

If it’s properly tightened it should not be able to go on crooked, only straight as you will not be able to turn the actuator otherwise. 

A sufficiently talented inept lineman can manage enough force to latch the actuator, even when it is crooked. And it takes a lot of leverage to unlatch it.

[carusoam]

On 11/24/2019 at 6:09 PM, Sabremech said:

A fuel cap is too difficult for an ordinary mechanic? Really? This myth that a Mooney requires a special mechanic is getting very old. 

Sabre,

My writing isn’t that bad is it?

The objective of my writing was to get Chris up to speed with what he needs to know to keep water from entering.... not bashing any mechanics or the people they work for...
 

There are four things that can leak related to the fuel cap...

I outlined them pretty clearly...

On the way there, I tried to cover...

 

1) an ordinary private pilot should be able to find what is leaking...(I don’t know Chris, but I believe he is capable)

2) an ordinary mechanic would only miss it, if he isn’t paying attention... (distraction can occur to anyone at any time)

3) A Mooney mechanic isn’t required for any Mooney maintenance but may have the experience to solve the problem quicker...

Yes, some people are going to like their MSC better than my mechanics at my home drome... that does get old...

 

So covering the choices Chris has...

1) proper cap  (mine was improper, he says his are good)

2) proper seals, two per cap... (mine was improper, he says his are good)

3) proper adjustment...(mine fluctuates on who touches it last, his looked like it needed help)

4) no rusted holes or missing sealant on the sheet metal the cap is mounted in... (mine rusted through)

 

I’m close to the edge of accidentally insulting the OP that has come here for help... by urging him to follow procedure... and at least find the source of the water intrusion... before it gets Beyond dangerous...

 

Now, I haven’t been to an MSC in a few years... my favorite Mooney mechanics are MSers... I do have one favorite MSC/mechanic around here.. but he is in Canada... a bit far to fly for a fuel cap adjustment...

I think... when I said Mooney mechanic... you may have mis-understood what I meant...

Or I didn’t say right... 

My apologies, A good Mooney Mechanic doesn’t need to come from an MSC... and an ordinary mechanic at an MSC may lack enough Mooney skills worth mentioning...

Was that more clear? 
 

The mechanic that builds Mooney Cowls from scratch, has STCs for Mooney parts, and other birds including corporate jets... is he not a knowledgable Mooney Mechanic?

I’m getting a touch better at this MS thing over the years... still not perfect.

Best regards,

-a-