I thought my breather valve was broken too. I could blow through the hose from the intake manifold. So i've found second hand two other valves, but those dit exactly the same. So, I've opened one of the valve's to find out how it works:
Picture (I'm not allowed to post images, try to fix this later...)
[img]h%20t%20t%20p%20://i16.tinypic.%20c%20o%20m%20/61k44jn.jpg[/img]
Can anyone with more than 10 posts, post this picture for me?
You can see the picture two posts below, thanks vins480t
The picture shows that it is always possible to blow through the pipe where the hose from the intake manifold is attached to. There is a direct connection between this pipe and the pipe where the hose to turbo intake is attached to through a small hole.
When the engine is running, there is always a low pressure in the horizontal pipe (negative pressure? vacuum? I don't know the right word at this moment
) Due to this the diaphram is sucked to the pipe and air can't flow between them anymore. Air is still allowed to flow through the small hole. When the crackcase builds up pressure, the diaphram is pushed back so the gases can escape more easy.
When the turbo is not building up pressure in the intake, air is sucked through the small hole. When the turbo is pressuring the intake manifold, there is still a low pressure in the horizontal pipe in the picture. In this situation air is blown through the small hole, but it will flow away to the turbo, as in this situation the turbo is creating a low pressure at it's intake side.
My valve had a split diaphram. There was a crack at the edge. This didn't affect the way the valve works described above, but made it possible to let air flow in from outside. Air can flow through the small hole right in the picture and through the crack in the diaphram. This might affect running at idle. But, the small hole at the right is covered with insulation, so I don't know of any air is flowing in this way.
