Fuel Leak - Pressure Gauge Line?

itsjames2011

itsjames2011

Pre-takeoff checklist
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Jul 21, 2014
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Chicopee MA
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Display name:
James
Upon departure yesterday I started to smell avgas and my fuel pressure took a dump. I returned to the airport, opened the cowl, and this is what I found. Is this the line that goes to the fuel pressure gauge? It hooks to a hose that goes to the carburetor in the other and goes up into the cockpit. Is it possible this could just be re flared on site and have a new compression fitting put on? There are no mechanics at the airport I'm based at.

https://youtu.be/fL5jdtyEoHo
 
itsjames2011 said:
Upon departure yesterday I started to smell avgas and my fuel pressure took a dump. I returned to the airport, opened the cowl, and this is what I found. Is this the line that goes to the fuel pressure gauge? It hooks to a hose that goes to the carburetor in the other and goes up into the cockpit. Is it possible this could just be re flared on site and have a new compression fitting put on? There are no mechanics at the airport I'm based at.

https://youtu.be/fL5jdtyEoHo
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Hard to tell from the pic, but some of those small lines are flared while some others are silver-soldered. If it's flared, the aviation flare angle is 37°, not the automotive 45°. Not likely anyone there has the right tool and it need a mechanic's signature anyway.

It looks like a poor setup in any case. The hose from the engine is only held to the mount by an Adel clamp, which can let the hose end wiggle as the engine moves, and that wiggling work-hardens the tube and cracks it. It's just going to break again, maybe with fire next time. It needs whatever the parts manual says it should have.

Dan
 
Dan Thomas said:
Hard to tell from the pic, but some of those small lines are flared while some others are silver-soldered. If it's flared, the aviation flare angle is 37°, not the automotive 45°. Not likely anyone there has the right tool and it need a mechanic's signature anyway.

It looks like a poor setup in any case. The hose from the engine is only held to the mount by an Adel clamp, which can let the hose end wiggle as the engine moves, and that wiggling work-hardens the tube and cracks it. It's just going to break again, maybe with fire next time. It needs whatever the parts manual says it should have.

Dan
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I fully plan on having it fixed by a qualified mechanic I'm just trying to figure our what to tell them when I call. Hopefully I can find someone that will travel to KCEF.
 
Looks like it broke because the copper line is too short. probably from being fixed last time. You may be able to find a copper cap at Homer Dan or Ace.
 
yetti said:
Looks like it broke because the copper line is too short. probably from being fixed last time. You may be able to find a copper cap at Homer Dan or Ace.
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It looked like copper in the vid but I wouldn't expect copper in that service. Do folks really use copper for fuel lines on their aircraft?
 
Clark1961 said:
It looked like copper in the vid but I wouldn't expect copper in that service. Do folks really use copper for fuel lines on their aircraft?
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Yes, and oil pressure lines. This isn't a fuel feed line, just a tap for a gauge.
 
N801BH said:
Yup...

Piper did......:yikes::eek::redface:
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Yep, it was cheap, light, and simple. No major problem really. Can you do it better and safer? Sure, but it will cost more money by a factor of 20 and increase the weight an even greater factor. It's all compromises.
 
Right before it is an orifice that is preventing the tank from being emptied on the firewall. The green is the key that it could be copper. Also that it probably has been leaking prior.
 
It could also have a ferrell on the line instead of a flare
 
yetti said:
Right before it is an orifice that is preventing the tank from being emptied on the firewall. The green is the key that it could be copper. Also that it probably has been leaking prior.
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It is copper tubing, and it's short. It should have a 1-2" loop in the length to prevent this cracking. It probably needs a complete replacement this time with a full length tube. It's a cheap repair.
 
Henning said:
It is copper tubing, and it's short. It should have a 1-2" loop in the length to prevent this cracking. It probably needs a complete replacement this time with a full length tube. It's a cheap repair.
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I hope that SOP is to replace copper lines at overhaul...
 
Clark1961 said:
I hope that SOP is to replace copper lines at overhaul...
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I doubt it. Heck, there's copper fuel plumbing way old on boats. If it's properly bent and mounted, it's pretty reliable. This is probably the OEM tube that has been broken and shortened before, and put into stress in the process.
 
Henning said:
I doubt it. Heck, there's copper fuel plumbing way old on boats. If it's properly bent and mounted, it's pretty reliable. This is probably the OEM tube that has been broken and shortened before, and put into stress in the process.
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Vibration in aircraft compared to boats, hmmm, I think boats win by a large margin.
 
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Henning said:
I doubt it. Heck, there's copper fuel plumbing way old on boats. If it's properly bent and mounted, it's pretty reliable. This is probably the OEM tube that has been broken and shortened before, and put into stress in the process.
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Cessna uses stainless line or a hose for that. Both are far superior to copper. In any case, the hose is stressing the copper and failing it.

I had a copper oil pressure gauge line break in flight. Lost most of the oil before I landed. A friend had a similar line fail in flight and lost the engine and airplane both. Copper should have no place in these applications.

Dan
 
Henning said:
Then it's up to the owner to pay to get rid of it.
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The problem with certified planes is you are at the mercy of the OEM spec....

They install junk.... You HAVE to replace it with junk...:mad2::mad2::mad2:
 
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I'm not all that familiar with Piper and I was shocked at how much copper was used on Cherokee 6 that Dave White was flying.


That said I've never been impressed with some of the cessna uses of rigid tubes either.
 
N801BH said:
The problem is certifies planes is you are at the mercy of the OEM spec....

They install junk.... You HAVE to replace it with junk...:mad2::mad2::mad2:
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Oh no, if you want to replace with high quality tagged hoses and a thru-bulkhead AN fitting, there is easy provision to make a minor modification like that quite simply.
 
Henning said:
Oh no, if you want to replace with high quality tagged hoses and a thru-bulkhead AN fitting, there is easy provision to make a minor modification like that quite simply.
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Interesting....... Good to know... TY.
 
Henning said:
Oh no, if you want to replace with high quality tagged hoses and a thru-bulkhead AN fitting, there is easy provision to make a minor modification like that quite simply.
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Not sure why they didn't do that to begin with. A firesleved hose is <$100 assembled and the fitting is <$15.

On the 1968 177, tho only rigid tubes near the engine is the primer lines and the ol' bourdon tube oil temp.
 
I was able to get a mechanic to come out and cap the line at Westover. I flew down to Simsbury Connecticut(4B9) tonight and tomorrow the whole thing will be replaced with a non copper flex hose :)
 
Things pilots are allowed to do under preventive maintenance

  1. Replacing any hose connection except hydraulic connections. Owners are allowed to replace any hose or hose connection except hydraulic connections, which also includes broken lines. You are also allowed to change such lines as:
    Cabin air hoses;
    Carburetor heat hoses;
    Drain hoses,
    Cooling air hoses for radios.
    Owners may replace static pressure lines except when used for IFR flight (see FAR 91.411); however, it is strongly suggested that you leave those to the A&P mechanic.
  2. Replacing prefabricated fuel lines. You are allowed to replace prefabricated fuel lines with approved prefabricated fuel lines for your make and model airplane.
 
yetti said:
Things pilots are allowed to do under preventive maintenance

  1. Replacing any hose connection except hydraulic connections. Owners are allowed to replace any hose or hose connection except hydraulic connections, which also includes broken lines. You are also allowed to change such lines as:
    Cabin air hoses;
    Carburetor heat hoses;
    Drain hoses,
    Cooling air hoses for radios.
    Owners may replace static pressure lines except when used for IFR flight (see FAR 91.411); however, it is strongly suggested that you leave those to the A&P mechanic.
  2. Replacing prefabricated fuel lines. You are allowed to replace prefabricated fuel lines with approved prefabricated fuel lines for your make and model airplane.
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Yeah, legal wise the avenue for the owner pilot to repair this is a given, however to completely comply, the job should be done the first time under supervision. This goes for A&Ps as well. If someone is comfortable and knowledgeable doing it, no worries.
 
Of all the funny things the FAA does testing for the ability to safely pilot a plane would also give them the skills to safely work on a plane kind of takes the cake. More rules from a day gone by.
 
Or one can install an electronic gauge and sensors & eliminate the copper lines and steam gauge. And get a totalizer along with it.
 
wsuffa said:
Or one can install an electronic gauge and sensors & eliminate the copper lines and steam gauge. And get a totalizer along with it.
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That would be the expensive solution, however, Fuel Flow is the first thing I added to every plane since having one come on my first. Knowing exactly how much fuel you have left at any given point is a wonderful thing. Having it tell a GPS that will warn you you don't have enough fuel to your destination very soon after the wind changes on you is downright awesome. Makes speed optimizing for range or mileage a simple exercise that you can continually tune. Probably doesn't make much difference in an Archer, but in the 310 it can lead to mid double digit per hour cost savings.
 
Henning said:
That would be the expensive solution, however, Fuel Flow is the first thing I added to every plane since having one come on my first. Knowing exactly how much fuel you have left at any given point is a wonderful thing. Having it tell a GPS that will warn you you don't have enough fuel to your destination very soon after the wind changes on you is downright awesome. Makes speed optimizing for range or mileage a simple exercise that you can continually tune. Probably doesn't make much difference in an Archer, but in the 310 it can lead to mid double digit per hour cost savings.
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Yep. It was one of the things that I installed in my plane that added the most value in terms of piloting safely. Particularly true when traveling out west with the airports few and far between.
 
wsuffa said:
Yep. It was one of the things that I installed in my plane that added the most value in terms of piloting safely. Particularly true when traveling out west with the airports few and far between.
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I added a fuel flow but kept the steam fuel pressure gauge :lol:.
 
bnt83 said:
I added a fuel flow but kept the steam fuel pressure gauge :lol:.
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Nothing wrong with that, but it is worth something to get rid of gas lines from behind the panel, especially ones that are leaking....

I put in a FP-5L which had both flow and pressure. It can be a primary replacement....
 
wsuffa said:
Nothing wrong with that, but it is worth something to get rid of gas lines from behind the panel, especially ones that are leaking....

I put in a FP-5L which had both flow and pressure. It can be a primary replacement....
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Seems to me that the type certificate still requires the original steam gauge to be present and working even if one STC's a better instrument into the airplane. I'd rather get rid of fuel pressure lines under that panel, too, and there are instances of them failing due to improper clamping or chafing. It's crazy to have pressurized fuel aft of the firewall. When I put the engine in a Glastar (E-AB) I found a pressure isolator that took fuel pressure from the engine and turned it into oil pressure to the gauge. Mounted the isolator forward of the firewall. It was nothing more than a couple of housing halves with a diaphragm clamped between them. The gauge side and the gauge line were filled with 5606.

Dan
 
Dan Thomas said:
Seems to me that the type certificate still requires the original steam gauge to be present and working even if one STC's a better instrument into the airplane. I'd rather get rid of fuel pressure lines under that panel, too, and there are instances of them failing due to improper clamping or chafing. It's crazy to have pressurized fuel aft of the firewall. When I put the engine in a Glastar (E-AB) I found a pressure isolator that took fuel pressure from the engine and turned it into oil pressure to the gauge. Mounted the isolator forward of the firewall. It was nothing more than a couple of housing halves with a diaphragm clamped between them. The gauge side and the gauge line were filled with 5606.

Dan
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It depends. Some of the aftermarket instruments are certified as "replacement for primary" and allow the removal of the stock gauge.
 
Dan Thomas said:
Seems to me that the type certificate still requires the original steam gauge to be present and working even if one STC's a better instrument into the airplane. I'd rather get rid of fuel pressure lines under that panel, too, and there are instances of them failing due to improper clamping or chafing. It's crazy to have pressurized fuel aft of the firewall. When I put the engine in a Glastar (E-AB) I found a pressure isolator that took fuel pressure from the engine and turned it into oil pressure to the gauge. Mounted the isolator forward of the firewall. It was nothing more than a couple of housing halves with a diaphragm clamped between them. The gauge side and the gauge line were filled with 5606.

Dan
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Depends on the plane and the flow meter. Not sure about current status, but at one time you could get an EI unit that was STC'd as a primary replacement. Most that they sell are used as secondary.
 
wsuffa said:
Depends on the plane and the flow meter. Not sure about current status, but at one time you could get an EI unit that was STC'd as a primary replacement. Most that they sell are used as secondary.
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More and more that I see being installed are good to be primary.
 
Dan Thomas said:
Seems to me that the type certificate still requires the original steam gauge to be present and working even if one STC's a better instrument into the airplane.
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Remember that STC means "Supplemental Type Certificate". If the STC says that the original gauge can be replaced by the new equipment, then you can do it, because the STC has amended/superseded the original TC.
 
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