chriscalandro

Lots of water in tank 67C

Recommended Posts

*Members that donate $10 or more do not see advertisements*

Ok.  It HAS to be coming from the cap.  I put new Orings on it (again) but it's still getting water.  I don't know how, but that has to be it.  Stand by for further investigations...


If it is not coming through the O rings, the sealant around the cap base may have failed. I’m pretty sure it is one of the fuel tank sealants used around the cap (at least it is used on the bladder caps).

Slightly pressurizing the tank through the vent may show the leak around the cap.


Sent from my iPad using Tapatalk Pro
  • Like 1

Share this post


Link to post
Share on other sites

 

This is what it looks like under the cap ring with sealant mostly removed.

 

771dd402b4dbaa6a268a44491af034ce.jpg

 

Old one removed.

 

c49fc2e020782da28bf7fbedfb8153dc.jpg

 

New style bladder cap and base installed.

 

c1f66b1f57ab57f8cbd21eb0f373065f.jpg

 

 

Sent from my iPad using Tapatalk Pro

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Chris,

You have been on MS for a year already...

are you looking for reasons to ignore the good advice given?

Adjust it a little to find the value they are offering to you...

Are you expecting a Marauder on a white horse to come in and point to the spot that is leaking for you?

The Marauder came in on a white horse and dropped off a bunch of pics that showed you what to look for on your plane...

 

1) Note the 90° Corner that is required to make the part... new, old, mild steel, SS, even for bladders...

If you have mild steel, that 90° corner stressed the surface of the part and causes it to rust and erode all the way through...

2) Look at the seal challenge depicted in the pics... if you think your plane doesn’t have sealant there... that would explain the leak you probably have....

3) Even though Marauder has bladders in his plane, now... what he is showing you is the before bladder pics...  get it?

4) about testing the seal at the caps... you can take it flying in the rain, and watch the bubbles emanating from the leaks... because that is what happens... low pressure on top (leak location)... high pressure on the bottom (vent location)... air moves from high to low pressure where the seal isn’t...

Or, you can take the advice from the same guy where he tells you how to pressurize the tank and find the leaks...

5) Wait... there is also a way to change all the parts to get stainless steel, new seals, and no leaks... and add some bladders too...   how far do you want to go?

 

How does that sound?

:)
 

Marauder might be on a mission... to help people that don’t want to be helped...:)

Chris is on the opposite mission... to feign not wanting help... while water keeps entering his fuel tanks...

Mooneys are unbelievably similar from the first ones to the last ones... so few changes have occurred through the years...

 

Best regards,

-a-

  • Thanks 1

Share this post


Link to post
Share on other sites

What are you talking about? None of those images are of the stock cap of a 67c. They are caps of later models or of modified tanks. 
 

the advice posted is not applicable to my fuel caps. Thank you, but the advice given here is not relevant. I’m sorry you feel so hurt that you’re advice was not helpful. 

lots of people have answers. Only a few have correct answers.  Not every Mooney is the same.

For the record Eric was correct. 
 

Edited by chriscalandro

Share this post


Link to post
Share on other sites

Chris,

That is a great pic of a well cleaned, unsealed, rust free, perfectly sealable piece of metal...

Does yours look like that, when the pic is taken from the same angle?

 

To solve a problem that you Actually have... it is probably best to start with pics of what you have...

Otherwise, you get a lot of theoretical solutions for problems you may theoretically have...

 

Speaking theoretically... my 65C had everything it needed to keep water out of its fuel... but in real life it was missing a detail that was near impossible for an ordinary PP to describe...

 

Got a tank of air?  Can you borrow one from the local FBO?

Best regards,

-a-

 

Share this post


Link to post
Share on other sites

Like I mentioned. Eric was correct. When I put the new orings in there must have been some debris in the channel. It worked for a while but then sliding it around tore up the rings on the inside. Couldn’t see it from the outside of the rings. 

Share this post


Link to post
Share on other sites

When you get the cap off, and o-rings out, give a look to see how smooth the surface of the channels are...

If something is tearing an oring, it is probably inhibiting the seal as well...

OSU is our O-ring guy...there isn’t anyone more knowledgable about Orings and fuel caps around here...?

 

Depending on how tight the fuel cap is... the ease of cocking it increases with tightness...

I have seen some grease used on the Orings as well... not sure if that is a proper material to use...

Best regards,

-a-

Share this post


Link to post
Share on other sites
On 11/24/2019 at 8:28 PM, DonMuncy said:
On 11/24/2019 at 8:28 PM, DonMuncy said:

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.

 

On 11/24/2019 at 5:09 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. 

This is why I handle (no pun intended) the fuel caps on my E during refueling. I don't care who I insult.

Many are not aware that the cap levers are designed to fold towards the back of the wing so as not to catch airflow and possibly open.

Share this post


Link to post
Share on other sites

O-Ring grease (such as Dow Corning Molykote 55) on the small, inner O-ring would be appropriate, as it is a dynamic O-ring.

 

  • Like 1

Share this post


Link to post
Share on other sites

Why dont you swap fuel caps and see if the problem travels? If it does travel and the o-rings aren't the problem, the hardware in the fuel cap might have worn down over time. That can happen and may need to be replaced.

James

Share this post


Link to post
Share on other sites
On 11/30/2019 at 7:43 PM, PilotCoyote said:

O-Ring grease (such as Dow Corning Molykote 55) on the small, inner O-ring would be appropriate, as it is a dynamic O-ring.

 

Isn’t DC55 meant for static orings and not dynamic orings?  That’s the stuff that makes it swell slightly correct? 
-Matt

Share this post


Link to post
Share on other sites
10 hours ago, MB65E said:

Isn’t DC55 meant for static orings and not dynamic orings?  That’s the stuff that makes it swell slightly correct? 
-Matt

I'm not aware of it's ability to swell the o-ring...I was taught to use it as a lube for installation, and see no harm to applying it to the inner o-ring in the cap, but there could be something better suited out there.... as far as DC55 keeping the o-ring lubricated for any length of time, I have no idea how long it would last.... I am curious whether EZ-Turn (sometimes used in fuel selector valves and primers to keep them operating smoothly)  might be a good solution, as it won't migrate when immersed in fuel- but I have no idea what it's low temp characteristics are..

  • Like 1

Share this post


Link to post
Share on other sites
18 hours ago, chriscalandro said:

I like the grease idea. Someone local here suggested dabbing them with petroleum jelly, I like that idea, I’ll probably do that as well. 

Petroleum jelly is the right lube for the fluorosilicone rings and okay for nitrile for a fuel-related application.   Silicone grease works well on the nitrile, too.

 

Share this post


Link to post
Share on other sites

Engine oil dribbled on the center shaft of the cap each time you add oil to the engine is as simple as it gets.  If any gets past the O ring it dissolves in 100LL.

Clarence

Share this post


Link to post
Share on other sites
1 hour ago, M20Doc said:

Engine oil dribbled on the center shaft of the cap each time you add oil to the engine is as simple as it gets.  If any gets past the O ring it dissolves in 100LL.

Clarence

I believe this was either DMax or Paul Loewen's recommendation as well.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.