[chuckwn]

I discovered this mess during a regular 50 hour inspection. After some poking around, the source turned out to be a loose primer line. The fuel was turned black as it leaked by the flared tube and got spattered on the firewall.

The cause was a warn adel clamp that isolates the relative motion of the engine and firewall. The primer line was sliding back and forth in the adel clamp. This motion was applied directly to the attach point of the flared tube causing it to become leaky.

Be sure to check to check those clamps for security!

This installation has 1675 hours flight time.

 

[Pat Stewart]

Fuel Line

Chuck,

For what it's worth I am not fond of that fuel line going through the firewall and making that sharp 90 degree inboard turn. I would install a 90 degree bulkhead fitting and use fire sleeved flex fuel lines from that point forward.

Pat

 

[Alan Carroll]

Chuck,

For what it's worth I am not fond of that fuel line going through the firewall and making that sharp 90 degree inboard turn. I would install a 90 degree bulkhead fitting and use fire sleeved flex fuel lines from that point forward.

Pat

I wondered if this might draw attention due to past threads on use of aluminum line and fittings forward of the firewall. I've got a similar setup and have been debating whether to change it.

Its hard to tell from Chuck's picture but depending on how its done the 90? bend isn't necessarily all that tight. From the point of view of fuel flow its less of a tight turn than that caused by an elbow fitting. I assume the line is supported on the back side of the firewall so that there's no flexing taking place.

Regarding flex fuel lines, both rubber and teflon melt at a temperature well below the melting point of aluminum. My solution was to wrap the aluminum line in firesleeve, secured with safety wire. The question is whether to change this line to steel; the answer depends in part on how difficult a steel line will be to fabricate.

 

[chuckwn]

Good suggestion

Another set of eyes is always a good thing. I will add firesleeve to the rigid line and the short section of line to the gascolator drain.


Thanks folks

 

[L.Adamson]

Another set of eyes is always a good thing. I will add firesleeve to the rigid line and the short section of line to the gascolator drain.

On the other hand..................I like the ease of inspection "without" fire sleeve. Mine will remain bare, to the gascolator.

L.Adamson --- RV6A

 

[Snowflake]

Another set of eyes is always a good thing. I will add firesleeve to the rigid line and the short section of line to the gascolator drain.

In this case you probably don't want to do that... The Aluminium line is likely to fatigue over time, and you'll want to monitor it.

On the other hand one thing you could do to increase safety is to remove the cable tie from the engine mount. If you must use a cable tie, put it around the adel clamp instead. On the mount, it will fret over time and wear a groove first in the paint and then in the engine mount.