Sump on bottom plane leaking

[Animosity2k]

I've noticed over the last month when I come to the hangar theres a blue stain on the floor from where my fuel drain on the bottom of the plane is consistently letting off small droplets of fuel. How do I prevent this? I've pushed it in and out a bunch and tried to clean it up w/ a towel thinking there was some debris on it? Anyone else have this issue?

[FlyingMonkey]

23 minutes ago, Animosity2k said:

I've noticed over the last month when I come to the hangar theres a blue stain on the floor from where my fuel drain on the bottom of the plane is consistently letting off small droplets of fuel. How do I prevent this? I've pushed it in and out a bunch and tried to clean it up w/ a towel thinking there was some debris on it? Anyone else have this issue?

Are you sure it's the valve itself, and not the gasket at the top of the gascolator bowl?  If it's the valve, it's just threaded into the bowl and can be replaced.

[GrassStripFlyBoy]

I'm not familiar with brand of drain valves installed on CT, but these were a 10 year change interval on my Cessna due to the O-ring seals degrading.  I carried a spare as once they start dripping it's more than annoying being fuel leakage.  Even if it was a piece of crud creating a leak and it stops, they are sort of a "rubber replacement" item and I'd say its time.  I developed a technique of removing the old one, holding thumb over the hole, and inserting the new one on the wing tanks, with minimal fuel loss - but have the rags ready for quick clean up.

[Tom Baker]

1 hour ago, Animosity2k said:

I've noticed over the last month when I come to the hangar theres a blue stain on the floor from where my fuel drain on the bottom of the plane is consistently letting off small droplets of fuel. How do I prevent this? I've pushed it in and out a bunch and tried to clean it up w/ a towel thinking there was some debris on it? Anyone else have this issue?

Most likely the valve. Order a couple of these from Aircraft Spruce, (https://www.aircraftspruce.com/catalog/appages/curtisquickdv4.php?clickkey=5626 ). I change these on all CT's as part of the rubber replacement. It is not a required item, but it saves these types of problems. Changing it can be a hassle. IIRC you will have to either drain the fuel, or remove the headliner and clamp the fuel lines from the wing. You will still have to drain the header tank. If it were me I would remove the whole gascolator from the airplane. Attached are a couple pictures.

IIRC the header tank uses a Saf-air valve, and they have replaceable o-rings.

[Animosity2k]

3 hours ago, FlyingMonkey said:

Are you sure it's the valve itself, and not the gasket at the top of the gascolator bowl?  If it's the valve, it's just threaded into the bowl and can be replaced.

Do you have a photo of the gasket you speak of? I'm only looking at this from the outside as I'd imagine I have to take a lot apart to see it from the inside. It just builds a little dribble up at the bottom but doesn't seem to ever stop. 

[Animosity2k]

2 hours ago, Tom Baker said:

Most likely the valve. Order a couple of these from Aircraft Spruce, (https://www.aircraftspruce.com/catalog/appages/curtisquickdv4.php?clickkey=5626 ). I change these on all CT's as part of the rubber replacement. It is not a required item, but it saves these types of problems. Changing it can be a hassle. IIRC you will have to either drain the fuel, or remove the headliner and clamp the fuel lines from the wing. You will still have to drain the header tank. If it were me I would remove the whole gascolator from the airplane. Attached are a couple pictures.

IIRC the header tank uses a Saf-air valve, and they have replaceable o-rings.

 

 

Tom, as always I appreciate your replies! Is this something I can do as an owner w/ no mechanical skills? I'm not to familiar w/ how everything works yet but I assume in the photo you posted that the large silver cylinder is the gascolator  and the bronze fitting on the bottom right is then the part that dangles out the bottom of the plane where I have my leak issue at, am I correct? If so is there any o-ring on the outside I can try to replace before getting so invasive? I may just leave the small drip, I can't believe I'm really loosing much. 

[FlyingMonkey]

If your airplane is an S-LSA it will require a mechanic or at least a mechanic to sign off.

[Animosity2k]

It is a S-LSA. Can I just somehow check the oring on my own or something without ripping it apart

[GrassStripFlyBoy]

Likely opening a can of worms - but here goes...

There is no exhaustive list of what an owner can and can't do working on their owned aircraft, there are advisory circulars and lots of commentary - hunt the FAA and web for these, easy searches and lots of articles.  The primary definition starts something around phrase "simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations".  We all know the PM items of oil changes and the sort, the key words I'm sharing here are words of "and the replacement of small standard parts".

Now, we can argue is the gascolator a complex assembly or not, I'd be of the opinion something designed for service (cleaning, examining sediment collection, etc) is within the scope of an owner working on.  Further, this part is "small" and "standard".  I'm sure others would state its a fuel system component and hands off, not looking to start a debate here, saying there is lots of grey on what is and is not a complex assembly.

Further I'm not saying you should attempt this.  If you feel up to it, and make the determination of what this is work wise relative to what I'm sharing, then be sure to note the work in log book, etc. This is where having a relationship with a local mechanic who knows you and your abilities is gold.  On my Cessna I'd also shoot an email to him, ask if what I was thinking is OK, get his blessing and use him for advise and tips for process, then all was kosher.  I understand this forum is the best source for CT insights, but any local mechanic knows this gascolator / drain valve typical stuff.  I go back to you can't have too many friends around the airport.

This sort of stuff is exactly why I went experimental category.

[Tom Baker]

If you have the type fitting shown in the picture I posted the seal is not replaceable, you must replace the whole valve. I posted a link for the valve. They do make a special socket for removal of the valve, a CST-716. The bowl may still want to turn when trying to remove the valve, but the socket will give you a better chance. Unless you drain the fuel or pinch the lines fuel will come out of there at about 20 gallons per hour.

The gasket Andy mentioned is a https://www.aircraftspruce.com/catalog/eppages/acs_06-00441.php .

I would not suggest tackling it yourself if you are lacking mechanical ability. 

[GrassStripFlyBoy]

Animosity - Something to consider is joining the EAA and connecting with local chapter.  Besides the homebuilder crowd, there are usually old A&P's around who aren't actively working as mechanics, but more than willing to come to your hanger to see your bird, and give a hand to help a fellow chapter member with this sort of stuff.  Some of the best people you meet are EAA crowd.

[FlyingMonkey]

1 hour ago, GrassStripFlyBoy said:

Likely opening a can of worms - but here goes...

There is no exhaustive list of what an owner can and can't do working on their owned aircraft, there are advisory circulars and lots of commentary - hunt the FAA and web for these, easy searches and lots of articles.  The primary definition starts something around phrase "simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations".  We all know the PM items of oil changes and the sort, the key words I'm sharing here are words of "and the replacement of small standard parts".

Now, we can argue is the gascolator a complex assembly or not, I'd be of the opinion something designed for service (cleaning, examining sediment collection, etc) is within the scope of an owner working on.  Further, this part is "small" and "standard".  I'm sure others would state its a fuel system component and hands off, not looking to start a debate here, saying there is lots of grey on what is and is not a complex assembly.

Further I'm not saying you should attempt this.  If you feel up to it, and make the determination of what this is work wise relative to what I'm sharing, then be sure to note the work in log book, etc. This is where having a relationship with a local mechanic who knows you and your abilities is gold.  On my Cessna I'd also shoot an email to him, ask if what I was thinking is OK, get his blessing and use him for advise and tips for process, then all was kosher.  I understand this forum is the best source for CT insights, but any local mechanic knows this gascolator / drain valve typical stuff.  I go back to you can't have too many friends around the airport.

This sort of stuff is exactly why I went experimental category.

Same, I got really frustrated with being able to do many small tasks, and not being legally allowed to do so.

The problem you get into, is that what you consider a "small, standard" part is likely different from the FAA interpretation.  And there are no clear limits to that description.  A cylinder valve is small, and standard (tens of thousands are out there!)...does that mean an owner is fine pulling a jug and replacing a valve?  Almost certainly not.  So...where's the line?  The answer legally is "wherever the FAA decides it is."

Best to just go experimental. 

[Tom Baker]

In my opinion simply changing the drain valve without removing the gascolator would be preventive maintenance. If you have to remove the gascolator from the airplane, as expect you will, I would no longer be consider it preventive maintenance due to the added disassembly. 

Removing the bowl and cleaning the screen, replacing the gasket, or changing the valve on the non fuel injected CT would be a different story. 

[FlyingMonkey]

12 hours ago, Tom Baker said:

Removing the bowl and cleaning the screen, replacing the gasket, or changing the valve on the non fuel injected CT would be a different story. 

Would you consider all those items preventative?  I would, maybe excepting the valve replacement.  Seems simple enough, but as Bill mentioned that seems to creep into "repair" territory.

[Tom Baker]

Yes I would consider all of those to be preventive maintenance, including replacing the drain valve.

[EB3]

Not long after I bought my CTLSi, I thought I had a fuel drain leak, but it turned out to be a leaky hose between there and the fuel pump. A factory clamp had cut very slightly into the hose, so a leak developed.  My A&P replaced the hose and clamps, which stopped the leak. 

[Animosity2k]

22 hours ago, Tom Baker said:

Yes I would consider all of those to be preventive maintenance, including replacing the drain valve.

Tom, I'll take a picture tonight of exactly what piece I'm talking about. You mentioned I need to gain access to the gascolator earlier to change this part out. However this comment here about removing the drain being preventative makes me thing maybe theres a way to just swap the drain and not take it all apart?

[DocRon]

I wanted to comment on Mr. Baker's comment above " Unless you drain the fuel or pinch the lines fuel will come out of there at about 20 gallons per hour."

I found a way around that when I had to service the filter on my CTLSi gascolator.  If you take out the screw on the in-cockpit fuel selector valve and pull that assembly away you are left with a metal "nub" sticking out that the fuel selector arrow fits over.  Just take you finger and thumb and easily turn that nub 180 degrees so that if you had the fuel selector arrow installed it would point straight down.

This shuts off the fuel from your wing tanks without having to drain those tanks or pinch fuel lines. All you have to do is drain the header tank.  When you turn the fuel selector back to the "up" position it refills the header tank in about 30-45 seconds.

[AGLyme]

1 hour ago, DocRon said:

If you take out the screw on the in-cockpit fuel selector valve and pull that assembly away you are left with a metal "nub" sticking out that the fuel selector arrow fits over.  Just take you finger and thumb and easily turn that nub 180 degrees so that if you had the fuel selector arrow installed it would point straight down.

That's how Flight Design USA does it... 

[Animosity2k]

2 hours ago, AGLyme said:

That's how Flight Design USA does it... 

I assume it can't turn down without the cover off? (Planes not in front of me to see)

[Tom Baker]

5 hours ago, DocRon said:

I wanted to comment on Mr. Baker's comment above " Unless you drain the fuel or pinch the lines fuel will come out of there at about 20 gallons per hour."

I found a way around that when I had to service the filter on my CTLSi gascolator.  If you take out the screw on the in-cockpit fuel selector valve and pull that assembly away you are left with a metal "nub" sticking out that the fuel selector arrow fits over.  Just take you finger and thumb and easily turn that nub 180 degrees so that if you had the fuel selector arrow installed it would point straight down.

This shuts off the fuel from your wing tanks without having to drain those tanks or pinch fuel lines. All you have to do is drain the header tank.  When you turn the fuel selector back to the "up" position it refills the header tank in about 30-45 seconds.

Thanks, I did not know that. I will give that in the future.

[Animosity2k]

On 4/14/2020 at 4:42 PM, Tom Baker said:

 

Tom the above photo, where is this at? Is it in the back with the BRS chute? Do you need to remove the chute to gain access?

[Tom Baker]

It is located in the left side baggage compartment. There is a panel with 4 screws that is removed. Also in this picture the clear plastic cover that protects the controls is also removed. You might be able to shoot up through the hole with the special socket and remove the valve, but in my experience the valve is normally so tight the whole can will want to turn. On the CT I normally remove the can from the gascolator to change the valve. With this installation it is easier to remove the whole assembly than to try and remove just the can, at least that is what I have found. Trying to reinstall the safety wire in place is not fun, but it is easy with it removed.

If I were going to try the special socket I would try removing the valve without shutting off and draining the fuel. If the valve comes loose don't take it all the way out. Place some rags in the area to catch any spilled fuel. It would be ideal if you had a helper to either hold a thumb over the hole when the valve comes out, or to help in case you drop something. I have replaced drain valves like this in Piper Cherokee wing tanks by using the thumb method. If you are quick you can do it without losing much fuel.

[Animosity2k]

26 minutes ago, Tom Baker said:

It is located in the left side baggage compartment. There is a panel with 4 screws that is removed. Also in this picture the clear plastic cover that protects the controls is also removed. You might be able to shoot up through the hole with the special socket and remove the valve, but in my experience the valve is normally so tight the whole can will want to turn. On the CT I normally remove the can from the gascolator to change the valve. With this installation it is easier to remove the whole assembly than to try and remove just the can, at least that is what I have found. Trying to reinstall the safety wire in place is not fun, but it is easy with it removed.

If I were going to try the special socket I would try removing the valve without shutting off and draining the fuel. If the valve comes loose don't take it all the way out. Place some rags in the area to catch any spilled fuel. It would be ideal if you had a helper to either hold a thumb over the hole when the valve comes out, or to help in case you drop something. I have replaced drain valves like this in Piper Cherokee wing tanks by using the thumb method. If you are quick you can do it without losing much fuel.

Tom what is the "special socket" you speak of. 

Thanks in advance. 

[Tom Baker]

https://www.aircraftspruce.com/catalog/appages/curtisquickdv53.php?clickkey=80614

No promises that it will work through the hole in the belly though.