PCV hose failure on a built RB25DET

[Alex787B]

Hi everyone,

Last Sunday on the Nürburgring I noticed my PCV hose was not doing that well :

https://youtu.be/clfarpgriyA

It was really soft, completely folded due to depression inside, I had to turn it a bit to improve the flow inside but it did not help a lot.
I don't believe this hose is stock when I look at the shape it has (looks like a basic hose coming from your local auto store) and was planning to replace it with a kind of reinforced Silicone one.

After speaking about that with friends I got advised not to use silicone as apparently the airflow charged with oil vapors could damage and rot the silicone hose from the inside. Some of them advise me to use rubber fuel lines, some others told me about steel braided lines (but honestly, I don't wanna start messing around with fittings and so on).

-> if anyone had to replace that one, what kind of hose did you use ? Obviously it must be soft enough to be routed from the cam cover to the intake plenum, but strong enough to keep its shape and carry the airflow inside...

Thanks in advance for your help, and please forgive me if that's a silly question.
Wishing you all a nice day

[KiwiRS4T]

Go to a hydraulic hose place (yes they exist) and ask them for a piece of hose the right diameter that is temperature and fuel resistant. Doesn't need to be steel braided - tell them the application and they will find you something suitable. It will be expensive and you may have to pay for a metre minimum.

[GTSBoy]

There's a lot of vacuum in that hose. You should investigate what is blocking the inlet end of it.

[Alex787B]

3 hours ago, KiwiRS4T said:

Go to a hydraulic hose place (yes they exist) and ask them for a piece of hose the right diameter that is temperature and fuel resistant. Doesn't need to be steel braided - tell them the application and they will find you something suitable. It will be expensive and you may have to pay for a metre minimum.

Thanks mate. I went to a shop that's specialized in automotive material, parts and tools. They gave me exactly what you said, temperature resistant fuel line and I got a full meter.

37 minutes ago, GTSBoy said:

There's a lot of vacuum in that hose. You should investigate what is blocking the inlet end of it.

I'm not sure there's really something blocking mate. When I press on it like in the video, I can feel the flow inside. I bought a new hose and when I compare it with the worn one, it appears to be way more rigid - I don't know where the old one comes from, but I'm sure it was just too soft to handle the vacuum... let's see how it'll be with the replacement one.

Thanks for your answers !

[hardsteppa]

When mine failed, i used aluminimum tube and a bending tool to make the stock s-shape, although obviously you could bend it to pretty much however you need. Then just use short joiners of oil resistant hose to connect to the manifold and pvc end. Will last pretty much forever, and was cheap.

[Alex787B]

12 hours ago, hardsteppa said:

When mine failed, i used aluminimum tube and a bending tool to make the stock s-shape, although obviously you could bend it to pretty much however you need. Then just use short joiners of oil resistant hose to connect to the manifold and pvc end. Will last pretty much forever, and was cheap.

Great way to solve the issue mate, will keep that in mind should the new hose fail ?

Thanks !