Not looking forward to this repair (Fuel Vent Hose)

[jmurtap]

Smell of gas in the cabin, my mechanic gave me a couple of locations to look at. Found the problem, and have the correct replacement line on the way. Sure does look like a pain!! Mechanic will be on hand, but any tips from those who have done this would be very helpful!!
Thanks

[Bruce Fenstermacher]

Janson, what are we looking at? The area does not look familiar.

[robw56]

Thats the fuel vent line where it passes through the wing root area into the cabin. I replaced all 4 of those hoses when I did my restoration project last year. They are somewhat difficult to remove and replace. You will have a harder time since I'm sure you have a headliner in your plane.

[wingnut]

Because that interconnect hose is shot, I would replace all 4 of them at the same time. Yes, headliner will need to be partially pulled from forward spar carry thru, then you will see where the rigid fuel line connects to the common vent which is installed on center of cabin top, just aft of top of windshield. That common vent also has short interconnect hoses from each tank vent fitting. It is a pain in the you know what, but I promise it will be well worth your effort to change all 4 at the same time. Once you gain access to the cabin top common vent, just cut the old "rubber" hoses off. Then cut the hoses at the tank interconnects. This will allow the rigid aluminum line between tanks and common vent to "float", and move about. Measure the length of all 4 rubber hoses before you remove them. Put the new hose, with new hose clamps on the tank fittings first. Use some dish soap for lube. It'll all make sense once you get started. Then all you'll lack is finishing up.

[wingnut]

Edit to add.......WOW, you still have those old green crimp clamps installed. Those hoses may be as old as the plane. Another testament to quality of yesteryear

[jmurtap]

I ordered enought stuff to do all 4, it may very well be worth changing all of them while I'm at it.

[Bruce Fenstermacher]

Now I see it and understand what I'm looking at. Yes you will have to pull down your headliner. And yes it is a bitch of a job.

Not necessarily getting the old off as you can carefully cut it of with a dikes. But the metal lines are very close and it is difficult slipping the new hose on. You have to push the hose all the way on the line on one side then slide it back over the adjacent line. Lubricating the inside of the hose or the metal fuel line with something that will not deteriorate the new fuel line is the secret.

[GAHorn]

I recommend engine oil or WD40 for lubricant. You can slide the hoses over the pipe almost completely...then slide them outward onto the tank fittings and onto the gooseneck after the overhead line is in place.

[n2582d]

Jason,
What's the tube going longitudinally? Or am I looking at a Whelen strobe cable?

While you're at it you might want to change out the AN931-3-5 (MS35489-4) grommets which the tubes pass through at the fuselage.

Fig. 18-9

EDIT on 8/28/15: Those grommets are not for the fuel vent tubes. They are small grommets with a 3/16" hole.

[jmurtap]

That's a good idea with the grommets, I'm not sure what the other lines are.

[mit]

Just pull the wing off.

[jmurtap]

Just for future reference, on check out there was a box to check to receive certification paperwork with select items. Is that some thing I should be getting? Being what it is I didn't think it was worth the cost. But it would be nice to know typical ground rules on such dealings with parts.

[cessna170bdriver]

I did mine about 5 years ago, and now Del get to do it again... I had the headliner down and the windshield out at the time, so access wasn't that bad. I don't remember what I used as a lubricant, but it must not have been the right thing, as I did expend a fair amount of effort sliding the new hoses around. The fact that those lines are beaded at the ends didn't help matters.

[Bruce Fenstermacher]

Just for future reference, on check out there was a box to check to receive certification paperwork with select items. Is that some thing I should be getting? Being what it is I didn't think it was worth the cost. But it would be nice to know typical ground rules on such dealings with parts.

Jason, this is the age old question. Different strokes for different folks. If I was buying something that I thought someone would question it's legality I might spring for the paperwork. For hardware and most things I wouldn't.

Depending on the organization performing the maintenance however, it is critical. If the 135 operator I work for has any parts including hardware on hand, they MUST all have tags or paper.

[DaveF]

One of the online parts places has a mouseover popup on that check box that says "If you don't know what this means you probably don't need it".