5 year rubber replacement

[jrthomas]

Has anyone found a better/cheaper way to do the 5 year rubber replacement? CPS price is $1300 and change. Seems outrageous!
.

[DesertFox4]

You can check out our other Rotax authorized service sponsor L.E.A.F. out of Wisconsin but likely they will be in the same ballpark price wise as they also are supplying Rotax authorized parts.
There are cheaper alternatives than using all Rotax authorized parts. Hoses can be purchased elsewhere at much less price per foot and perform well. Some parts may only be available from Rotax which are pricey. There have been discussions about substitute items like carb. boots in the past on this site. Lots of posts about alternative hoses for cooling system use and fuel hose alternatives. Motor mounts are available many places. I purchased mine from Kitfox Aircraft.
Good luck with the project.😀

[Av8r3400]

I have a strong opinion that most of the 5-year rubber replacement is not necessary.

I have learned from "inside" people I have spoken to much of this stems from the idea that Rotax has no idea how the engine is mounted in the aircraft and where it is stored, so they recommend a worst case situation for these parts. On an open cowled airplane parked outside in Phoenix or Miami has the same standard applied to it as a closed cowl airplane in a hangar in Wisconsin.



Do you replace all the rubber components on your car every 5 years?

[jiott]

I heard Mike Busch, the nationally known and respected aircraft maintenance expert, once say that the Rotax 5-year rubber replacement instruction was probably overkill for an engine that was hangared and flown regularly. He thought 10 years might be more reasonable. This was not an "official" position of his, but was an answer to a question about it after one of his EAA webinars.

[PapuaPilot]

I totally agree with the last two posts. Ten years seems very reasonable. During your condition inspection we should be looking at the condition of the rubber hoses. What should we be looking for? Here is what the Quest Kodiak maintenance manual says about inspecting hoses:
Fluid Lines and Hoses: Inspect for leaks, cracks, bulging, collapsing, twisting, dents, kinks, chafing, proper bend radius, security of attachment, discoloration, bleaching, deterioration, and proper routing. Check rubber hoses for hardness/flexibility and metal lines for corrosion.


Realize that a manufacture, whether certified or experimental, can only make recommendations for maintaining their aircraft. Only the FAA can make something mandatory. Only the FAA can make things mandatory. On certified aircraft the FAA mandates or approves things via AD notes, chapter 2 of a POH "Limitations" and ATA chapter 4 "Limitations" in maintenance manuals.

[109JB]

I would definitely replace the cab boots at 5 years. Hoses can likely go longer but the carb boots have the weight of the carb and air cleaner cantilevered off of them and they do crack with age.

[Jcard]

Purchased a model V with almost 1700 hours and 19 years on the rubber with the exception of the carb boots.
Declined to do a test flight before getting it done, lol.
Probably would be fine but that is pretty excessive.

[Dave S]

My experience reflects the comments that Larry, Jim and Phil have contributed. It's all about condition, how that can be determined and environmental exposure.

After doing my first 5 year replacement, it was real clear that I had taken a lot of perfectly good items out of service.

The carburetor sockets, where I have the airbox installed on the engine, were indistinguishable from the new ones I put in except for the slight odor of 91 octane corn free autogas. I bent and folded the lips of the carb sockets and couldn't find any cracks or any other defects and they were still pliable. Without the airbox, I suspect that vibration and movement can taken a toll eventually, but not sure that would be 5 years - have seen some that were run till they broke after 18 or so years - that's pushing it .

The diaphragms inside the top of the carbs were both pliable and free of cracks at 5 years but you can't see them on preflight.

Still running the original NAPA V-belt on the aux alternator - still shows no signs of deterioration on annual condition inspection. Ditto on the short connector hoses between the airbox and the carbs.

The radiator hoses and heater hoses are pretty cheap anyway. Also - if I do any maintenance disconnecting them (like when the radiator was replaced or the heater repaired) they get replaced anyway. Many times on replacing a hose it needs to be slit to be gracefully removed.

Oil hoses (Parker) were cut open when removed and no cracks or swelling was evident inside or out and all were still flexible.

I have used fuel injection hoses for the fuel lines, same story.

The coolant hoses used on the engine cylinders seem to be pretty tough - replaced them but no flaws found on the old ones.

The fuel pump cannot be viewed internally for inspection so I don't have any problem with replacing that - don't think I would want to test the limit on that anyway (but the old one is retained for a spare.)

On thing is obvious. Rotax does not give a rat's elbow about anything that is not part of the engine. As an aircraft owner/maintainer we look at everything like the vent lines and fuel lines within the airframe and those little sight gauge tubes that need replacement once in a while so me can actually see how much fuel is in the tank.

What is the most troublesome rubber part I have had experience with? That would be those pesky "specialty tires of america" which can't seem to go more than 4, or at the most, 5 years without developing cracks in the grooves down to the cord in spite of careful attention to inflation pressure and the lack of ozone generating equipment in the hangar. I have yet to come anywhere near tread wearout before they had to be replaced due to groove cracks. We'll see how the goodyears last now.

So this year I am doing the 5 year a little later,

Have to agree that an extremely conservative shotgun approach to this deal without regard to use, environmental conditions and actual condition can result in throwing away perfectly good parts and increasing the cost of operation unnecessarily.

[Av8r3400]

I would definitely replace the cab boots at 5 years. Hoses can likely go longer but the carb boots have the weight of the carb and air cleaner cantilevered off of them and they do crack with age.

Use these (Link) and you won't need to replace them every 5 years. Far superior to the Rotax items.

[jrthomas]

Use these (Link) and you won't need to replace them every 5 years. Far superior to the Rotax items.

Yea, I'm a believe in JBM products. I used to have to replace sockets on my CGS Hawk 503 every couple of years. They would always show signs of dry rot within a short time. I went the JBM route and never changed them again. I just recently ordered new JBM carb sockets for my 912. I haven't changed them yet. Annual time is coming up in December and almost 5 years since I completed my model 4 got me to thinking about rubber replacement. I'm inclined to agree that total rubber replacement is unnecessary at 5 years. My main issue is the oil and coolant hoses. I'd like to find a source of good quality hoses but the sizes are hard to find. They are sized in mm and don't cross reference closely to standard sizes. Thanks for all the good advise.