Hose clamp problems

[lv2plyguitar 172]

I have been having hose clamp issues.  The first problem was a hose clamp on the upper nipple for the rotary valve shaft housing.  The clamp completely broke.  Later the nipple broke off when the end smacked the motor mount.  I pulled the engine to fix.  Upon inspection I noticed that the bottom hose clamp for the rotary valve shaft housing was badly damaged and about to break as well (the bottom was not hitting anything).  What are you experiences with this and what type of clamps should I use.  The type of clamp I use is similar to the picture I have attached. 

 

Thanks for your help.

[BryceKat 125]

That's what I use. Bryce

[dholly 718]

I used band clamps, much kinder to the hose covering.

[Mendlerr 4]

I just replaced all my plastic snap clamps with the metal work clamps you have in your picture. I was also at an auto store last week and saw miniature t clamps. I love t clamps, much better then the work gear style. Im with you though, I have been finding alot of worn out clamps on my airplane and I had one break last week

[SuberAvid 617]

Jeff, I use the ones like you show but be sure you use the high quality stainless steel ones and not the cheaper soft metal ones.  I have seen both types from China manufacture but name brand ones will be the better quality.  Usually the USA made ones are high quality.  The good ones are stiff and springy and hard to pinch out of round.  The failures I have had are usually the gear cuts in the band part failing.  The trick is to get them very tight but not over tight.  Sontimes you have to bring them up tight and then before each flight or so, snug them up again because the hoses squeeze and form some rather than just trying to get them too tight initially and breaking them.

 

It took me a couple months of doing this to my water hoses on my Subaru becuast I have quite a few fittings on it and after flying theere would be no drips, but after the plane sat for a few days there would be a drip hear and there.  Finally after a couple months of tensioning them before eachflight all the drips stopped.

 

On the softer hoses like the fuel line, I have cut strips of thin cardboard like cereal boxes are made from and wrapped it around the hose and put the clamp over it.  The small diameter ones are the hardest to feel good about and the band clmps are the best but have very small size ranges so you have to get exactly the right size.

[C5Engineer 1170]

Sounds like maybe you are overtightening them? I've used those on everything for years and never seen one break. I am replacing my entire fuel system this year during my conditional. Guess I will be looking very close at all my clamps while I'm replacing hose.

[dholly 718]

If you are registered on the Rotax-Owner.comwebsite, go to:

Rotax-Owner.com Forum > 4 Stroke Technical Questions > Fuel lines for a 912 ?

Good discussion about clamps. Rotax uses the Oetiker brand/style one ear band clamps on both fuel and oil systems. Oetiker kits are available from Amazon, fleaBay, Grainger, Sears etc. Or, source mini size screw drive band clamps (not worm drive clamp) typically used for fuel injection systems. They apply even pressure and will not cut outer sleeve. I've never seen the pricey 'T-style' aviation band clamps in that small a size. Personally, on the 582 oil system, I would probably feel comfortable just using nylon double-grip ratchet hose clamps. They are pretty damn strong and would eliminate the screw head clearance/interference issue you are having.

[akflyer 1427]

I just use a double wrap of safety wire and then  pull it down tight.  I have not had a leak or broken wire in over 300 hrs of flying the plane.