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Fuel and Oil Hose Life??

AndyRV7

Well Known Member
Do you guys service your hoses based on a 10 year manufacturer recommendation? It came up at my annual this month. The hoses have no signs of wear or imminent failure but they are 10 years old. Thanks!
 
I replaced all my hoses at 6 years. I think Cessna and Piper service manuals say 5 years.

I replaced my hoses with teflon-lined hoses from TS Flightlines. I think those are not life limited. Plan to leave them until engine overhaul.
 
I did mine at 10 years. TS Flight line made me a full set and re-used by fittings, so the price was not bad.
 
Andy, depends on what you have for hoses. All the Mil H8794 hoses, like Aeroquip 303, or Stratoflex 111 should be inspected at each conditional, and replaced at the 8 year mark MAX. Yep, they may look good and clean with no drips, but I'll bet if you removed them and tried to do a flex test, it would sound like Rice Krispies--snap, crackle and--oh boy.

Teflon isnt life limited under NORMAL usage, but certainly inspect them at conditionals.
Just helped a builder with a 9 year old teflon hose where the firesleeve had a cut in it from a rub on a Mag. NOTHING wrong with the hose, but since he wanted the assembly longer, we changed it anyway. Inspection was unremarkable. (lol thats a new word I learned from our Radiology friends)

Yep check them, no matter the age.

Tom
 
Thanks guys. I guess they do need further consideration. My mechanic mentioned specifically that they were flexible (among a few other good sounding things) but old is old.

Are hoses "standard" on an 0-360 in an RV-7, or does the builder fab them for the particular project? I'm just wondering if you can buy a "kit" of hoses and just swap them out.

Tom, my family is all in Conway. Maybe I'll have to come visit you in the near future.
 
Andy, depends on what you have for hoses. All the Mil H8794 hoses, like Aeroquip 303, or Stratoflex 111 should be inspected at each conditional, and replaced at the 8 year mark MAX. Yep, they may look good and clean with no drips, but I'll bet if you removed them and tried to do a flex test, it would sound like Rice Krispies--snap, crackle and--oh boy.

I won't discourage anyone from replacing hoses at reasonable intervals. But just as a datapoint, both times I have replaced/rebuilt the fuel and oil hoses on my RV-6, the stainless braided Aeroquip hose I took off the plane after several years in service was indistinguishable from the new hose stock I used for replacement. Still flexible, if I handed both old and new hose to someone they would not have been able to tell which was several years old.

But I still rebuild the hoses inside of ten years for peace of mind.
 
What should a full replacement cost these days? I guess I have to figure out the smartest way to go about this now.
 
Sam, stainless braided hose is in 2 forms===rubber/neoprene liner, and teflon.
Most of what we are talking about for the 8 year replacement/refirbishment was 303/111 hose--rubber/neoprene liner, nylon reinforcement braid, STEEL reinforcement braid (nope not stainless) then the cotton, supposedly oil resistant cover. Well the cotton absorbs moisture, fluids etc, and causes the STEEL braid to rust and after many cycles gives you the Rice Krispies sound.
Stainless braid, on the other hand, doesnt rust so it maintains (supposedly) its flexibility. But then the rubber liners can deteriorate from fuel additives, oil temps, many cycles, and begin to crack ( or as my Radiology friends say "fracture").
Weve seen them just fine in the plane and working over many years. They take a set and seem fine. But take them out , move them around then do a leak/pressure test on them, and see what happens. MIGHT surprise you.
Teflon hose seems to resist all of these bad things, mainly due to the higher fluid temperature rating of the liner vs rubber liners.

Tom
 
Andy, yes there are general standard lengths for the 7, O-360 as long as the the accessories are in the plans stock location. Carbed engines are easier than FI engines, because of the different servos, sumps and even exhausts.
Flow transducers in carbed planes are becoming more common, so that changes things too.
 
Sam, stainless braided hose is in 2 forms===rubber/neoprene liner, and teflon.
Most of what we are talking about for the 8 year replacement/refirbishment was 303/111 hose--rubber/neoprene liner, nylon reinforcement braid, STEEL reinforcement braid (nope not stainless) then the cotton, supposedly oil resistant cover. Well the cotton absorbs moisture, fluids etc, and causes the STEEL braid to rust and after many cycles gives you the Rice Krispies sound.
Stainless braid, on the other hand, doesnt rust so it maintains (supposedly) its flexibility. But then the rubber liners can deteriorate from fuel additives, oil temps, many cycles, and begin to crack ( or as my Radiology friends say "fracture").
Weve seen them just fine in the plane and working over many years. They take a set and seem fine. But take them out , move them around then do a leak/pressure test on them, and see what happens. MIGHT surprise you.
Teflon hose seems to resist all of these bad things, mainly due to the higher fluid temperature rating of the liner vs rubber liners.

Tom

Tom, I'm not suggesting anyone delay replacing hoses. However, the stainless braided hose with rubber lining that I've used in the RV-6 since 1999 have never shown any form of failure or lack of flexibility each time I have rebuilt them. This gives me confidence the hoses are reliable for my service intervals.

Just another data point.
 
Tom, I'm not suggesting anyone delay replacing hoses. However, the stainless braided hose with rubber lining that I've used in the RV-6 since 1999 have never shown any form of failure or lack of flexibility each time I have rebuilt them. This gives me confidence the hoses are reliable for my service intervals.

Just another data point.

My mechanic said the same thing. From what I remember, all the things that you can check for including the crunchy sound weren't happening with my hoses. I'm not making an argument one way or another.

So Tom, what do a set of hoses go for for my app? You can PM me if you like. Thanks.
 
Hoses are cheap and easy to replace. Set a time frame to replace and inspect for leaking annually. A metal tag attached to each hose gives replacement specs. :cool:
 
Still flexible not a good test

I had just had my annual condition inspection done by an A&P. He said the fuel hoses still felt good (steel braided rubber) -- flexible.

Turning on fuel pump for the next flight I smelled gas.
I took off the cowling, turned on fuel pump and saw gas spewing out through the steel braid!

Granted it's high pressure (40 PSI) and I run mogas.

Now I'm using non-steelbraided hoses and replace them every 3 years.

Finn
 
I had just had my annual condition inspection done by an A&P. He said the fuel hoses still felt good (steel braided rubber) -- flexible.

Turning on fuel pump for the next flight I smelled gas.
I took off the cowling, turned on fuel pump and saw gas spewing out through the steel braid!

Granted it's high pressure (40 PSI) and I run mogas.

Now I'm using non-steelbraided hoses and replace them every 3 years.

Finn
everyone's worst nightmare!
 
I went nine years 685 hours on my 303's. I know folks who have gone much longer, but youre taking your chances. Mine where still in great shape. I cut a couple open for inspection.
I package up the hoses and sent them to Tom to copy.

One caution. The Teflon hoses are a bit stiffer than the 303. I had to modify some routing as a result so it may not be an exact swap. My 303's where within tolerance for bend radius and the Teflon could make those turns but I didn't like how they "loaded" some of the fittings so I changed the routing a bit. Not a big deal and Tom's product with integral firesleeve makes for a cleaner install.
 
On a carbureted O-360, the following are the hoses I remember needing:

1. Gssolater to fuel pump
2.:Fuel pump to carb
3. Accessory case to oil cooler
4. Oil cooler to accessory case
5. Fuel pressure line
6. Oil pressure line
7. Manifold pressure line

Did I miss anything?
 
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Sam, are using mogas?

Tom

Non-ethanol premium 90% of the time, the remainder is 100LL.

Once again, I'm only relating my experiences, not trying to encourage a particular hose replacement protocol and certainly not being argumentative.
 
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Sam, we also are not trying to be argumentative. We are just relaying information based on our experience.

Tom
 
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