Engine Silicone Hose Replacement?

[Compass790]

Originally Posted by thinwater

As I said, whole bus and truck lines have gone to silicone, and then gone back after experiencing problems. It is not cost. It is pluses and minuses. They work out best on trucks with impeccably maintenance, where AF is checked frequently and there are zero oil leaks. Hose connections, particularly in the larger sizes, are more prone to leaks, because the hose grows and shrinks.


I'm not sayin' they aren't good. I've speced them in chemical plants. But they are not always better and generally ONLY makes sense if there is a specific issue, like very high temperatures. In fact, standard hose failures nearly always trace back to installation errors, often with the clamps, chafe, or hose routing (too hot, sharp bend, or not supported).

I'm not doubting your experiences but it does seem strange your assertion that silicone no good for oil. I use silicone instead of gaskets on gearboxes & sumps with no problems & it's not even gasket silicone.
. I will continue to do so UNLESS I experience problems.
Have no experience with silicone hose as the rubber ones last so long why worry?

[a64pilot]

Silicone hoses will not work for fuel and or oil.
I believe it turns them to goo, they swell and burst of course.
Silicone gaskets are not likely the same thing.
Silicone as an element is basically sand? So I doubt a silicone hose is actually the element silicone.

[Compass790]

Originally Posted by a64pilot

Silicone hoses will not work for fuel and or oil.
I believe it turns them to goo, they swell and burst of course.
Silicone gaskets are not likely the same thing.
Silicone as an element is basically sand? So I doubt a silicone hose is actually the element silicone.

Hmmm,
Well there must be silicone & silicone as a quick google search finds this:https://www.allports.nz/category/250...es-accessories

Says specialist silicone hose can be used for fuel & oil. Don't have a dog in the fight but just curious as happy enuff with rubber

[Boston Blackie]

A64, sand is not silicone. Silicone is an elastic polymer with a backbone of alternating silicon and oxygen atoms. Sand contains elemental silicon but no silicone.

[a64pilot]

Got it.
Poor attempt at trying to illustrate that maybe just because something had X as a marketing name, that maybe there is more to it than that.
Example, I seriously doubt that there have been any actual rubber radiator hoses made in a long time, but most of us still call it rubber and it’s understood what we are talking about, whether it’s actually rubber or not.

When sampling aircraft turbine engine oil, we found out that the sample tube has to be cleaned out before use or the oil analysis will come back as high silicon, indicating dirt in the oil, but it was actually something, we thought silicone in the sample tube.
Funny, cause the tubes were sealed on both ends and you had to cut the ends off to use them.

I’d bet that if silicone hose is permeable to water / antifreeze, that one of those four plies is likely Buna-n or something that isn’t permeable to water / antifreeze. I don’t know that , but as many millions of silicone hose kits for kids hot rod Japanese cars are sold every year, they have done something to eliminate the problem.

[Compass790]

Originally Posted by a64pilot

Got it.
Poor attempt at trying to illustrate that maybe just because something had X as a marketing name, that maybe there is more to it than that.
Example, I seriously doubt that there have been any actual rubber radiator hoses made in a long time, but most of us still call it rubber and it’s understood what we are talking about, whether it’s actually rubber or not.

When sampling aircraft turbine engine oil, we found out that the sample tube has to be cleaned out before use or the oil analysis will come back as high silicon, indicating dirt in the oil, but it was actually something, we thought silicone in the sample tube.
Funny, cause the tubes were sealed on both ends and you had to cut the ends off to use them.

I’d bet that if silicone hose is permeable to water / antifreeze, that one of those four plies is likely Buna-n or something that isn’t permeable to water / antifreeze. I don’t know that , but as many millions of silicone hose kits for kids hot rod Japanese cars are sold every year, they have done something to eliminate the problem.

I bet you are right as same as 4 ply "rubber" hose probably has little rubber in it.
Wont be rushing to buy something that is 10x the price & does the same job anyway.
Guess it looks pretty tho.
Would be dressing up a turd in our engines case

[a64pilot]

They aren’t for everyone, however I bet silicone hose is cheaper than the “correct” hose from Yanmar.

[thinwater]

There are silicone formulations that are very good with oil. For example, some of the best anti-drainback valves in oil filters are silicone. Curiously, the oil resistant formulations are not used for many of the hoses used on engines. They are optimized for AF instead. Go figure.



You just need to study the specs.

[Simi 60]

I have been replacing all of our original hoses on our 855 with blue silicone and T bolt clamps.

One day I'll give her a birthday and make her look all pretty like these ones.

[GeneM]

My mechanic told me to not use silicone for a turbo charger hose (about 2 1/4 inch on Cummins 6BTA) because of the pressure and getting very hot.

I didn't change it and so far it outlasted a few other OEM hoses!

I also use a silicone hose for the turbo oil drain - hot oil. It's 20 years old and going strong.

[Q Xopa]

Originally Posted by GeneM

My mechanic told me to not use silicone for a turbo charger hose (about 2 1/4 inch on Cummins 6BTA) because of the pressure and getting very hot.

I didn't change it and so far it outlasted a few other OEM hoses!

I also use a silicone hose for the turbo oil drain - hot oil. It's 20 years old and going strong.

Hmm, interesting. I was under the, quite possibly wrong, impression, that heat resistance was the main benefit of Silicone.

I guess it can be another case of different Silicones?

I know on the Helicopters I work on they have braided stainless steel, teflon lined and silicone covered hydraulic hoses. The silicone covering is supposed to be for fire resistance. The turboshaft engines also have silicone fire seals, silcone RTV'd on. I'll see if I can get a pic today.

[GeneM]

Originally Posted by Q Xopa

Hmm, interesting. I was under the, quite possibly wrong, impression, that heat resistance was the main benefit of Silicone.

I guess it can be another case of different Silicones?

I know on the Helicopters I work on they have braided stainless steel, teflon lined and silicone covered hydraulic hoses. The silicone covering is supposed to be for fire resistance. The turboshaft engines also have silicone fire seals, silcone RTV'd on. I'll see if I can get a pic today.

I'd guess you are right about the heat resistance. My experience supports that. I think the mechanic has an automatic default to OEM. I did alot of worrying about the hose that faded with time. Thanks for helping to bury the worry.

[Q Xopa]

Originally Posted by GeneM

I'd guess you are right about the heat resistance. My experience supports that. I think the mechanic has an automatic default to OEM. I did alot of worrying about the hose that faded with time. Thanks for helping to bury the worry.

Being an OEM myself, Im all for OEM by default too. Except in cases like this when the OEM is saying things like change them every 2 years. Or when the OEM stuff is obviously less durable than the alternatives, usually to cut production costs.
Im sure someone can say if we use non OEM stuff or dont follow OEM recommendations changing them every 2 years could void warranty. Personally keeping working is more a prioity than warranty.