Vacuum hose restrictor

[stevefh]

Hi all, S4 parts manual page 43.03A,part numbers  A912E2583K Vacuum hose ‘T’ piece to non return valve and A912E6452F (nla ?) Restrictor, pulsation damping.              I was expecting this restrictor to be made of metal but mine has partly disintegrated and collapsed and seems to be made of plastic or rubber. I am replacing this vacuum hose with silicone of 3mm I/D.    Does anyone know the diameter of this restrictor bore? Thanks for any help 

[stevefh]

Hi all, what is the source of the pulsation and is the ‘T’ piece push fit or screw in ,does it require sealant ?  Mine rotates and may be the source of an air/ vacuum leak.

[drdoom]

The vacuum source pulsates due to the nature of a reciprocating piston engine, and is particularly intense at or near idle conditions.

Cheers

[stevefh]

Hi all,Steve thanks for your reply. I have taken a good look at The crankcase breather valve system on my S4 ,my esprit has the restrictor after the non return valve as per parts manual plus one at each end of the pipe that runs from the cbv to the nrv,has anyone else got these? The last two are still intact and have a bore of 2mm.At idle surely this would allow very little crankcase fumes into the inlet manifold rail.

Previously I have removed the pipe going to the back of the air box and replaced it with a filter to air, as I had a little oil at the turbo. I know others have done this and some put in a catch tank and some left it open. Did any of you block off the small pipe cbv to nrv to “T” piece. What is confusing my understanding of this system is that this “T” piece also connects to the vacuum pipe to the fuel prv  a vital function for correct running .Anyone fully understand this system and would there be any problems with blocking off this small pipe to the  cbv. Thanks for any help.

 

 

would be