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Nomadicram

Member
I was told by an A&P that I should replace all my braided hose lines every six years. He showed me where each hose has a date tag and, of course, all my hoses were older than six years. He seemed to base his recommendations on a current Piper AD. This was all news to me. I searched the archives and couldn't find anything in the Forums concerning recommended replacement time for braided hoses. Is the A&P right?
Thanks,
Mike
RV-7, O-360
 
i talked with several hose manufacturers about this issue at Oshokosh a couple of years ago and asked point blank what their recommended hose life was. They all said "that is determined by the designer of the application" - they wouldn't give a recomendation.

Who knows where Piper got six years (if that is, indeed correct).
 
Nomadicram said:
I was told by an A&P that I should replace all my braided hose lines every six years. He showed me where each hose has a date tag and, of course, all my hoses were older than six years. He seemed to base his recommendations on a current Piper AD. This was all news to me. I searched the archives and couldn't find anything in the Forums concerning recommended replacement time for braided hoses. Is the A&P right?
Thanks,
Mike
RV-7, O-360
Click to expand...

FWIW

Beechcraft requires mandatory replacement of all flammable fluid hoses at 60 months on turbine aircraft. Maybe he got it from some directive like that. Beechcraft's lawyers do a really good job of covering their you know what. It sounds like Piper's lawyers are similar.
 
I'll bet it comes from the AD for old Cherokees with original 601 type stainless braid-covered oil hoses with synthetic rubber linings. The heat from the oil slowly bakes the rubber, and the hose routing goes pretty close to the exhaust pipes and muffler where it gets baked in spots even more quickly.

I had a Cherokee 140 for about a decade, and if I remember correctly it's actually 8 years, not 6. Also by installing modern teflon-lined hoses, the recurring AD for mandatory replacement was terminated for PA28 and PA32 models which had oil coolers mounted at the rear of the engine... but models with front-mounted oil coolers, like my poor old Cherokee 140, the mandatory replacement at 8 years or 1000 hours was kept in the AD, even for teflon hoses, since the hoses still ran close to the exhaust system and the FAA was afraid the hoses would still be getting cooked over time in those spots.

My Cherokee was equipped with new teflon hoses with the engine overhaul just before I bought it, and 8 years after that I had them replaced with a brand new set of teflon hoses as per the AD. The 8 yr old hoses were still like new, and I salvaged the perfectly good firesleeve off them and some of that is now flying on my friends RV-8 as extra heat protection around the throttle cable under the engine ;)
 
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On Learjet aircraft the only hoses that are life-limited are rubber hoses. If the hose is teflon it is on condition.
 
I'll quote from Aeroquip AEB 170A. "Service and shelf life of Aeroquip Teflon hose are unlimited for all practical purposes. However, experience has shown that service life on impulsing applications may eventually be limited by fatigue in the wire reinforcement. Maximum service life on such applications is best determined by the operator based on experience." Since most all aerospace teflon hose is essentually similar, then Stratoflex, Titeflex, Teleflex, are also similar. Even conductive industrial versions have similar life.

Properly installed, with no abrasions, the hose should have unlimited life. NOW---if it is located in a high heat location even with firesleeve, you can damage a teflon hose. But, for our discussion, and the environment we use it in, it should be a 'lifetime' hose. We arent talking about the space shuttle.
Tom
 
I have to second Tom on this one. Provided that the hose isn't being "damaged" in any way, the life expectancy is very very long.

We offer a 10 year warranty on our conductive Teflon hoses. If you decide to replace them after 10 years, Tom and I have data on every hose we have ever built and can replicate them at that point. It would be great for business if everyone replaced their hoses every 5 years. However, we intentionally use such high quality materials that you most likely won't have to do that. :):):)
 
plehrke said:
My local A&P IA has told me 5 years.
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When an A&P or IA (or for that matter anyone) tells you something like that, just ask innocently for them to show you where that is written down. Nine times out of ten, they heard it from someone else, or if it is written down, it was by a particular airframe manufacturer, and doesn't necessarily apply to anything else.

BTW, I have had old-style oil hoses blow out in flight, so I check hoses carefully for flexibility and condition!
 
After 8-10 years most rubber hoses are getting pretty stiff and I will "suggest" replacement. Fluid hoses are obviously critical to engine operation, a fuel/oil hose failure will not end well.
 
When you say stainless steel braided hose, that could be rubber lined hoses or teflon lined. I have seen various replacement dates stated by certified airplane and helicopter OEM's for the rubber lined hoses like the Aeroquip AE601/701 hoses. I have never seen a replacement date for teflon lined hoses like the 666 type. In fact, in some cases I have specifically seen OEM's specify that once you replace the rubber lined hose with teflon lined the replacement dates don't apply.

Go teflon.
 
The Mooney service manual says to replace rubber hoses every 12 years but for Teflon hoses it's on condition. One more thing about Teflon. The hoses take a permanent set after being installed for a while. It doesn't mean they're bad, but if you R&R one or move it to access something, be careful because you can kink the inner liner. It ruins the hose but it's not apparent in a visual inspection.
 
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