From all the info i gathered/serached on, silicone hose CAN be used for vacuume lines and coolant lines safely

On the other hand it should NOT be used for any oil or fuel application. (becasue the silicone can break down with oil exposure, et, et)

Comments from the material/chemical gurus...

 

That is my understanding as well.

-Max

 

thanks max....

 

In theory...

But I still haven't heard from anyone who has had silicone vacuum hoses for 5+ years without any problems.

Is it reasonable to put any material all over an engine bay and hope that it never sees oil?

 

>>Is it reasonable to put any material all over an engine bay and hope that it never sees oil?

hehhe, this is funny, but getting a touch of oil on the outside of a silicone hose is much different than haveing very hot oil constantly flowing through it.

 

I don't know. Is it necessary for the oil to be flowing? If the oil is in the engine bay, then it is definitely hot. And if it is touching the silicone then bad things could happen. Oil doesn't just wash off in water, so it might be there for a while.

I'm not an expert in this area, just trying to learn. Actually, I have been looking for any excuse to go with silicone instead of viton 'cos I want the pretty red hoses, but I just don't want to compromise reliability for looks.

That silicone vs. viton experiment is pretty scary. The real question is how much oil do the hoses see. Nobody can seem to agree on this.

Until we start hearing from people with silicone hoses in 5 years, I think all we can do is speculate.

 

My experience with silicon hoses is just the intercooler couplers. The previous owner used silicon and the whole time I had it the hoses would slip off and eventually started to crumble when I would slide them back on and crank the hose clamps down. I since bought a foot of the hose that is made specifically for turbo applications and I am loving it. If the vaccuum lines see anywhere near the oil that the intake sees then I would in no way use silicon for my vaccuum lines. That is why I havent done vaccuum lines yet, I would also like to know how much oil gets into these hoses. I dont the oil on the outside is going to be enough to worry about, the hose to my boost gauge has plenty of standard engine oil/dirt/other crap on it and is doing fine.

 

I have had to use a silicon hose(called Purosil I think) on my oil drain off the turbo for a couple of days to get me out of trouble and after about 300miles of hot oil flowing through it, it showed no sign of breaking down! I wouldnt be to worried about using it on vacum lines.

 

Have you guys seen these?

http://www.geocities.com/MotorCity/.../hosedebate.pdf

http://www.geocities.com/MotorCity/...55/hosetest.pdf