Jump to content

Which 5 year rubber part Replacement kit? Which Fuel Line?


Ed Cesnalis

Recommended Posts

The damage is still from over crimping. The fuel line is used all over the world with barbed fittings, just don't crush it to death. Would the other fittings be better like on the fuel pump , sure, but even the Rotax factory fittings on some of their own hose is barbed. They use ferrules on that hose, but the key is they use the right one and only crimp it so far. Enough to hold and seal it, but not cut it.

 

post-6-0-07028300-1353441941_thumb.jpg

 

 

Roger,

 

I spent some time today with the failed hose, a barbed fitting and a clamp. I wanted to see how much force it took to clamp the hose so tightly that it would cut it at the barbs. It didn't take any clamping/crimping force at all because the hose isn't getting cut at the barbs. There is a line being left at each barb but it is not a cut it is a step, it is a change where the inside diameter increases due to shaving by the barb as it is inserted.

 

The change in the inside lining to a shiny smoother appearance where it was over the fitting isn't from being tightly crimped it is from having the original inside lining shaved away. The strands of material at the innermost barb that can be seen are shavings that are still attached, all of the other shavings are or were in my fuel system somewhere.

 

The damage is done and the shavings are in the fuel line before the crimping even begins. A little oil makes the insert easier but it still shaves at least when I test it.

 

Carburetion hose shaves less than fuel injection hose because the carburetion hose is permitted to expand its diameter much more than fuel injection hose due to the difference in the mesh size that is used to obtain the target PSI for the hose.

 

Conclusion:

  • Gates is correct, rubber fuel line and barbed fittings are not compatible due to the sharp ferrules and serrated teeth.
  • If rubber fuel line is used with barbed fittings lower PSI carburetion hose is preferable to fuel injection hose because the lower PSI means more ability to expand resulting in less shaving as the hose is inserted on the fittings.

Hint: Pre-soaking the line in hot water may expand it enough to reduce or eliminate shaving.

Link to comment
Share on other sites

  • Replies 163
  • Created
  • Last Reply

Rotax, FD and the three distributors don't have any power here and it's up to you to get the correct info. just like it is with many other items with flying.

 

For the 5/16" fuel injection hose some people had a problem with, no one ever said you couldn't use 3/8" ID (6/16") to fit over the hose barbs without any forcing or damage. Owners could have used AeroQuip hose too.

 

 

Everyone needs to remember that it's ultimately up to the owner with their mechanic to decide what hose to use. Rotax, FD or CPS do not specify, dictate or regulate what should be used. That's the very thing many argued about here, they can't make me. They were right, you are on your own, they can't make you and you don't always get to pick and choose what they can make you do. The Rotax distributors all use something different as far as hose to. Now go out and demand that the three Rotax distributors all use the same thing. That would be another interesting conversation. It boils down to owner edification.

 

It is not a Mfg issue, but one of information that each owner and or mechanic should research and decide on before these maint. items even come due.

 

Everyone wants to blame all these other people, but it's our decision because it isn't regulated nor does it have and specs.

The FAA says that ultimately the owner is responsible for maint. done or not done on an aircraft. Everyone wanted less regulation, now you have it. Remember the old saying, "Be careful what you wish for".

 

Many here have said that Rotax, FD or the FAA can't force them to do some maint., use certain parts, or re-pack chutes or take classes, but now you want it regulated so someone is responsible and accountable. So if they regulate it then you'll be upset that you were forced to do something or use something you didn't like or a mechanic complained about. You can't say you want regulation (parts and maint.) and then complain about regulation. We don't get to pick and choose what just fits this persons needs because ultimately it won't fit the other guys and he will complain your imposing on him. So like everything else in life half will like it and the other half will fight it. The more you demand regulation the more it will cost you and that's what many already don't like.

 

Here is an example;

The red Teflon hose that feeds the carbs is supposed to be replaced on the 5 year hose program. Many have complained they shouldn't have to do that and flat stated they can't make me, I'm going to do it on condition. Some won't do it, but with more regulation you will spend $340 for that hose. Let Rotax, FD, the FAA and the rest come in a dictate a hose type and brand and you may face a real mandatory hose change at triple the cost because everyone wanted better un-destructible hose. If you complain enough FD could post a "Service Directive" which is binding and make you buy hose only from them and a certain type for a lot more than you pay now and you'll be forced to do it on their terms. You may argue that hose isn't a flight safety issue, but many here say it is and it has forced people to land. That's a flight safety issue.

 

 

The key to all maint. is forethought, research and planning. There is more technical info on this forum than most forums and the answers for most of our questions can be deemed from right here.This is why I have always preached that mechanics should have more education on the Rotax, have all the manuals and read forums like this to learn before an issue arises.

Don't you remember when everyone said they can't make me go to school or do such and such maint. or use specific expensive parts. So then you have those very people work on your plane that said you can't make me learn. I guess they told the powers to be.

 

 

 

The real thing to do here as an owner is to stay informed and read. Talk to others who have done certain procedures and have your mechanics call other mechanics who have done these procedures too.

This forum is a pretty tight family and we tend to watch out for each other, so advise your maint. people to call and ask questions from other people. When I haven't done a certain procedure before I read the manuals, research the web and call another mechanic or a factory rep. If someone fails to learn before a procedure it isn't a procedural fault, just an individual one.

Link to comment
Share on other sites

Hi Ed,

 

In some post quite a while back we determined the 5/16" FI hose was too small and required way too much force to push it over the barbs without some type of sloughing of small hose pieces.

 

We can't police and be everyone's savor out there, but we can make a difference right here on this forum. That's why I count myself lucky to learn from some of the knowledgeable people we have here. I read these guys every day and learn. Everyone has something to bring to the table from time to time.

On a personal note it's my job to learn every day so I can do my best when you come here. Failing to plan and learn is not an option nor a place for me to be lazy.

Link to comment
Share on other sites

Hi Ed,

 

In some post quite a while back we determined the 5/16" FI hose was too small and required way too much force to push it over the barbs without some type of sloughing of small hose pieces.

 

We can't police and be everyone's savor out there, ...

 

 

http://www.cps-parts...?idproduct=1483

 

If it is too small why is it in the kit designed by Roger Lee for the CT? Why is this still on the WWW?

Hope no one else gets sucked in today.

 

You know Roger, in stead of coming back with the same rant time and again it would be helpful if you did admit that that hose damage is in fact not from over-crimping and that the hose is not cut. You have a louder voice than I do but only one of us is correct here.

 

If the hose was cut it would have to be changed for sure, fuel would be coming in contact with layers that were not formulated for it. But its not the case I can bend the hose backwards and see there is no cut at all. The barbs are not high enough to cut through the wall.

 

When you insert rubber hose over the barbed fitting and encounter resistance you will shave some amount of rubber. The amount of resistance can be misleading because the resistance varies with conditions.

 

Once you install the hose there is no way to check the amount of material removed by the barbs when the hose was inserted.

 

Roger you are correct, owners have to be informed, mandating maintenance and correct parts isn't enough. Lets be loud and clear

  • Look at the photo above carefully before you use the hi pressure fuel line that is currently sold by CPS for the CT.
  • Don't be fooled by Roger Lee's name.
  • IF you install rubber over barbed fittings do a test first and cut it away to see how much material is being removed by the barbs
  • If you are concerned about over-crimping test first as well.
  • Do a followup inspection and clean up, rinse and repeat if necesarry.

Link to comment
Share on other sites

Hi Ed,

 

Like I said before, I didn't know my name was attached to their advertising. I didn't make up the kit, just helped identify all the parts needed along with a few other folks here on the forum. The old CPS made up the kit and the new CPS just used what was given them not knowing any different or anyone else at that time. My over crimp comment was from the pics displayed, but I already knew it was too small and tight and could and would shave bits off. I informed the forum and I informed CPS more than once. I have ask that my name be removed from the CPS posting and anything past all the above I have absolutely no control over other than to post the info here which I did immediately when we found out the fuel injection hose wasn't working out. Not a single person knew up front that the fuel injection hose could cause an issue on installation. If you didn't have a problem within the first 5-25 hrs then you probably won't. It isn't actually an issue after it is installed and when done correctly only if the install isn't a clean job with precautions. It has been successfully used on hundreds of planes so it isn't an absolute issue with everyone.

 

I'm like you Ed, just one guy that found an issue and let people know. Beyond that I have no other control or authority. This has been such a hot topic here on the forum lately there should not be a single person that reads this forum that can say they are not informed.

I think we have ridden this horse as far as we can go. It's time to look to the future and go to the next horse.

Link to comment
Share on other sites

First Roger, is this a safety issue? If so, the standards say FD is responsible for notifying, and, providing instructions for these issues. Second, as good as this site is, there is no requirement or even suggestion by either FD or Rotax that all owners and anyone who works on an FD built airplane log in here. "ctflier" as a forum name does not necessarily indicate that this is a Rotax mechanic's forum. Third, you have said there are analyses, practices, and methods that Rotax only reveals to those who attend their classes.

This is not good for Rotax, FD, or those that fly their machines.

You have mentioned on this forum that you have testified in court cases. How would you have testified if Ed's problem would have ended in a worse manner? This is dangerous stuff - it is worthy of a safety alert so everyone doing this work will know!

Link to comment
Share on other sites

Hi Doug G,

 

I would have said in court just what I said here and the court would probably agree. Is it a safety issue? Depends which backyard you are in and which fence you look over. It is only a safety issue if you fail to plan and get all the info before a procedure. That wasn't done here. Sometimes people think they are informed because they stopped with the first thing they saw or read and didn't follow through far enough. Rotax along with many other organizations and Rotax class attendees have stated that everyone should go and that there is info you need to know and applying some other engine information or technology may not be applicable on a Rotax. This fact has been known by most owners for 21+ years. But several here and on other forums said you can't force me to go and learn or even do what is known to be a good practice, so they didn't and there is a price to pay for that. You are right that there is no requirement to read any forum or even go learn. All this comes down to is still the owner and mechanic. The information is out there, failing to educate yourself is not a failure of the system, but a failure from the individual or mechanic. Everyone has said you should attend a Rotax class there are things to learn so why not do it after many years of hearing those very words from thousands of people. You want to issue a Safety Alert. Were you not one of the one's that said we are not required or don't have to follow adhere to SB', SA's or SI's? That the hose should be on condition only. Several here stated they didn't have to do anything unless it was a SD or AD. Who here said you can't make me do a chute re-pack? That's until someone dies then they want to do the re-pack. So do people want more regulation to protect them from themselves or be allowed to make a choice. Doesn't seem like people can have it both ways and make each decision fit every persons needs in the US. One half the population will be upset at any decision.

 

Whether someone is a member here or not the info is out there and has been for years. Just because me, you or a group didn't know or research and learn before we did something didn't make it wrong.

This is no different than the owners that put in after market parts and when it fails complain to Rotax it should have worked and now they are stuck with a very expensive repair bill. These are simple parts; rubber carb bowl gaskets, starters, wrong hose clamps, different fuel pumps, wrong oils, ect.. The list goes on and then add on poor and sloppy maint which many times accompanies these things cost saving measures people want to do.

 

The driving force behind all of this is money. They didn't want to spend the money for a class or a Rotax part. It was too expensive. Are parts cheap or the class cheap. Hec no, I'll be the first to admit it, but I fly and I take friends and I maintain other peoples planes so for me it's the right thing to do and no one said flying was a cheap or even a safe hobby. There will always be risk.

 

The very bottom line is no matter what plane you fly or in what category, we as owners need to always and continually learn before we jump and when there are that many people that say it's important, verses a few who don't, then it's time to error for more education and to make sure our mechanics are on the same page. No one said it was easy, If it was I wouldn't spend days, weeks and months and money doing research to keep me and my friends safe.

 

The FAA says it's ultimately the owners decision and responsibility to do things right, have them done right and take the responsibility.

 

This is exactly why I got my Repairman License. I have worked on Rotax a other planes and helicopters for years. Then when I had this one plane before the CT. I had this mechanic always doing something I knew was wrong. I would tell him it was wrong and show him, but he would argue he didn't need to do it that way and that he had been a mechanic longer than me, but he would screw things up anyway and I was still stuck paying him when I had to re-do the work.

 

I had enough and went to many schools. Several Rotax schools over the years and then maint. school. So the info is out there, what do you want to do get to the info?

We are our own worst enemy's. We want and demand freedom of choice until it cost us then we want to blame someone else. It's human nature.

You don't have to even want to be a mechanic, just having the knowledge puts you a 2-3 steps up.

 

 

 

You don't even need Rotax, FD or CPS. Ed found his info on Jegs. The info is out there.

Link to comment
Share on other sites

For me I see nothing more that is redeemable from furtherance of this topic. We are all now aware of the hose. The only thing left is for people to talk to CPS if you so choose. Beware that may backfire and they stop selling any kit at all then you'll be totally on your own. They told me once they were going to stop selling any fuel hose for the CT kit and we were on our own. They may have felt it a little drastic at that time, but I bet not this time. That was from the last time people blamed it on them and FD.

 

As Will Rogers said:

Be thankful we're not getting all the government we're paying for.

 

 

This may apply here.

Link to comment
Share on other sites

For me I see nothing more that is redeemable from furtherance of this topic. We are all now aware of the hose. The only thing left is for people to talk to CPS if you so choose. Beware that may backfire and they stop selling any kit at all then you'll be totally on your own. They told me once they were going to stop selling any fuel hose for the CT kit and we were on our own. They may have felt it a little drastic at that time, but I bet not this time. That was from the last time people blamed it on them and FD.

 

post-6-0-22482500-1354116389_thumb.jpg

 

post-6-0-70788700-1352380117_thumb.jpg

 

There are 2 classes of contamination that I am dealing with as a result of inserting barbed fittings into fuel injection line.

  1. Immediate hazard: The first class is the material that is completely removed. This fitting provided a "clean shave" and resulted in an alarming amount of this class of contamination that was found in the carbs, filters and fuel pump.a
  2. Long term hazard: The 2nd class is from the same source but it has not yet completely severed but instead pushed just beyond the fitting.

After 2 filter / carb clean outs the immediate hazzard is being handled but what do I do about the long term? If I take some of the damaged hose from my aircraft and pull off the debris that is still attached it takes a good pull, it makes a snap. Is it safe?

 

It has been suggested that since all the hose damage is on the last 2 inches of hose that we could cut the hose shorter and remove the damaged ends. This is a bad plan as it will only start the cycle over from the beginning again. So at this point I have no plan and no direction.

 

Flight Design and Rotax need to consider changing to beaded fittings that are compatible with rubber hose. What would be the cost of changing fittings along with changing hoses?

 

Obviously Roger wants me to forgo making a claim with CPS so that they don't get pissed off and stop selling us fuel hose. I sure wish they would have stopped selling us fuel hose upon the previous incident! Roger if you don't let the chips fall where they may you will put more people and their wallets at risk. Safety first.

 

PS much can be learned by replicating the damage. The problem isn't over-crimping the line is not being cut, the problem is the inherent incompatibility between rubber lines and barbed fittings and that problem is amplified by the use of fuel injection hose.

Link to comment
Share on other sites

With over 400 production airplanes here in the states don't you find it odd that none of the new airplanes had hose problems with the barbed fittings. I have done about a half dozen hose changes now with no problems that I know of. The only place that I have used the Gates fuel injection hose is the replace the the Gates fuel injection hose on the fuel pump supplied by Rotax. For all the other fuel hoses I have used the DIN spec hose called for in the FD parts book. I do think that Gates had a bad batch of hose, and this is what caused the Rotax SB on the fuel pump hoses. I plan to continue to use the DIN spec hose called for by Flight Design. BTW Flight Design also calls for the DIN spec hose in the parts book for the fuel pump even thought they were delivered with the Gates hose supplied by Rotax.

Link to comment
Share on other sites

With over 400 production airplanes here in the states don't you find it odd that none of the new airplanes had hose problems with the barbed fittings. I have done about a half dozen hose changes now with no problems that I know of. The only place that I have used the Gates fuel injection hose is the replace the the Gates fuel injection hose on the fuel pump supplied by Rotax. ...

 

Great question Tom,

 

I just got some of the original "Wurth" hose from my hangar and I cannot replicate the damage using this hose. The first big difference I see is the Wurth hose has a smooth interior wall where the Gates hose from CPS has a textured inner wall. Without the rough inner wall to grab onto the barbs seem less prone to remove material upon inserting.

 

There are variables at play and at each connection some differ.

  • fuel injected vs carburetion ( stifness )
  • smooth inner wall vs textured
  • aggressive barb design vs less agressive design
  • hose size ( 5/16" more problematic than 1/4" )

Link to comment
Share on other sites

'Roger if you don't let the chips fall where they may you will put more people and their wallets at risk. Safety first.'

 

Do you mean if more people use Gates Carberator hose rather than Wurth hose?

 

Geeze, how many engine outs due to fuel line contamination, out of 400 CTs, or more ROTAX end-users in the Experimental category can be expected as engine rubber changes pick up?

Link to comment
Share on other sites

I'm trying to reconcile the fact that the Gates hoses have larger I.D.'s (.25" and .32") than the DIN Wurth (.22" and .30") and should br marginally easier to install and have less abraiding when pushed over fittings but this is not happening. It does appear that the Gates Barricade hose has provided trouble free results (i.e., no rubber debris in the system). Perhaps the Gates Barricade hose has a rubber formulation similar to the Wurth and is more flexible and offers improved resistance to abraidment compared to standard and/or injector Gates.

Link to comment
Share on other sites

Dick, the hose that CPS is selling and that gave such a bad result is Gates Barricade Fuel Injection. It seems pretty clear that it is the tight mesh in the fuel injection hose that is the problem over the barbs. The hose that keeps getting referred to as Barricade is the Gates Carburetion Barricade hose and it has a looser mesh and a much lower PSI.

Link to comment
Share on other sites

'Roger if you don't let the chips fall where they may you will put more people and their wallets at risk. Safety first.'

 

Do you mean if more people use Gates Carberator hose rather than Wurth hose?

 

 

 

I mean the resolution in May solved nothing and was the basis for my mechanic using the CPS product supplied for our CTs. Here we have another incident and Roger wants to end the discussion and even suggest that a complaint to CPS might "backfire". If we end it here, saying the only problem is me and my failure to read Roger's prior posts then nothing will be solved again.

Link to comment
Share on other sites

Dick, the hose that CPS is selling and that gave such a bad result is Gates Barricade Fuel Injection. It seems pretty clear that it is the tight mesh in the fuel injection hose that is the problem over the barbs. The hose that keeps getting referred to as Barricade is the Gates Carburetion Barricade hose and it has a looser mesh and a much lower PSI.

 

Ed, I guess I was confused due to the Gates fuel injection hose I purchased from my speed shop was not Barricade but just generic high pressure Gates injection hose. This was very stiff and I was and still am concerned about possibly damaging the fittings due to the extreme effort required to install it. The good thing is that I didn't seem to get any debris from this non-Barricade injection hose. I now "get it" that the hose giving problems is the Gates Barricade injection hose.

Link to comment
Share on other sites

... I now "get it" that the hose giving problems is the Gates Barricade injection hose.

 

Yes that is the hose that CPS is selling in the CT kit. According to Gates all rubber hose is incompatible with barbed fittings and somewhere above there is a photo of debris from Gates Barricade Carburetion hose.

 

I think Gates is right to an extent, barbs sliding against rubber will cause damage but in some cases its just some microscopic scraping but in others like some of mine it results in an alarming amount of contamination.

 

If you don't at least test first when you install you have to decide if the pressure required to insert was enough to lead to a bad result.

 

Beaded fittings would be one answer, A hose that gives consistently good results would be another, test installs then cut away and inspect might be helpful.

Link to comment
Share on other sites

Just an FYI,

 

CPS is in full swing designing a new CPS catalog.

The other news is they are not going to use the that fuel injected hose any more and they are switching.

 

Ed and all,

 

If you want FD to make a change fill out the "Service Difficulty form" on their website and send it to FD. List why you think the fittings should be changed and what type of fittings you think are best.

Link to comment
Share on other sites

Just a few pics and 2-3 nice phone calls. I talked to them today. They only needed investigative evidence with a viable solution.

Rotax will not intercede here. That is left to all kit and factory built aircraft Mfgs and individuals that have experimental's.

If you want FD to consider anything at all you need to send in Service Difficulty forms with good reasoning, evidence and a viable solution. If you want a fleet wide LOA to add fittings retroactively then ask for such. It's just the system. Cool analytic and problem solving heads will prevail and it's rarely an overnight solution.

Link to comment
Share on other sites

From what I hear, I believe you guys are about to get all the regulation you wanted and maybe then some at twice the cost and it may include more than you wanted..

 

I did a hose change today on a 2007 CTSW and it had 3 brands of hose right from Rotax and FD. Which one do you want?

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...