In replacing the vacuum pump valve, I checked the one way valves and found one does not hold a vacuum or presure either way. It is the Crankcase Vent Valve, part no 06A133528D and is shown here in ECS:

https://www.ecstuning.com/b-kayser-p...6a133528d~kay/

It is not one of the "generic" check valves, it is only for B6 1.8t.

Is this valve like all others and truly one way? I am asking before I replace it unnecessarily.

Many thanks,

John

 

Hi,

I replaced mine a couple of months ago as it had begun to deteriorate - had a whiteish fading on one side. I didn't check if it had either vacuum or pressure... sorry. The car did run better after changing but then I also fitted a new cat and adjusted my turbo flapper adjuster at the same time.