Lago Blue

I certainly found a vacuum leak on my car due to the old seal that connects the Booster to the large vacuum hose from the Intake-manifold.

From your top left photo and your text, have you replaced the original check-valve with a common "T" fitting just forward of the Booster in the above large vacuum hose? If so, your biggest vacuum customer, the Booster, cannot store what it may need when you apply the brakes. Yes, this substitution may also be the cause of your stalling issue.

Heix

Now i need help for getting check valve part number for vacuum diagram. I lost mine, because it was broken.

Check valve nr 4. in this diagram.

Heix

In this http://www.audizine.com/forum/showth...es-058-905-291 thread i found some part numbers.

2 way is : 058 905 251
3 way is : 07C 133 529 A ( used to be 058 905 251 D )

Is that one im looking for 07C 133 529 A?

Heix

a8 (1996 2.8 12v )have suction yet pump (058133753) instead of check valve. Whats the difference?

Lago Blue

I have no idea what difference a suction pump may make however, in your diagram above, number 4 has two hoses attached. In your photo above the valve pictured has connections for three hoses. This may be what is meant by 2 or 3-way valves. Which does your car require?

Heix

My car require 3 way valve. The same valve what is in my picture rounded with white. In picture third hose is not connected.

Lago Blue

"Do you mean hoses from cam covers to noise damper?"

Yes.

"These are new, but there are some squeezed corners where air may not pass."

If you can re-use the original black plastic quick-connectors which have O-rings to help sealing, you can connect them with some 5/8 inch I.D. (inside diameter)(0.6250 inches/15.8750mm) hose.

This diameter of hose is not too large that you can't run them without kinking them closed. It has a substantial wall thickness which will prevent it from sagging, and trimmed to a suitable length, works perfectly. Use the inherent curve that the hose comes with to help make the bends you need.

Check to make sure your OEM quick-disconnects are not cracked and that the O-rings are in good shape.

I used two "straight" OEM connectors on the starboard side, one straight and one 45° connector on the port side, the 45° one at the Cam-cover. I think this is the same as the original arrangement.

The O-ring material appears to have been changed to an possibly more heat-resistant orange coloured material on the later A4 series cars.

With a couple of short lengths (each <i>approximately</i> 6 inches (152.4mm)) of high-quality rubber hose, you can now connect the Cam-covers to the Noise-damper without "squeezed corners".

You can read the specification of the hose I used in this photo. It is fuel line from a Marine store.

DIY Cam-Cover Vent Hose and OEM Quick-Connects Assembly photo:

https://forums.audiworld.com/picture...ctureid=185587

Heix

1992 y audi 100 do not have plastic vent hoses and plastic ends. I have seen these in 1996y 2,8 A8 and 1996 y A4. In 1992 year audi 100 there are rubber bended hoses from factory, but they were cracked and i switched them with straight rubber hosees, therefore there are squeezed points where should be corner. I fixed hoseses with metal clamps to cam cover and to noise damper. But in hoses there are squeezed points. Is there my oilloss?

Lago Blue

"Is there my oil loss?"

Not exactly the location perhaps, but may be the cause of oil loss; elsewhere. Apparently with very little positive pressure build-up in the crank-case, oil will be forced out at other locations where it otherwise wouldn't be. Audi wrote a TSB (technical service bulletin) on this:

TB C15-04-02 dated August 31st, 2004 titled:"Diagnosing Oil Leakage from Gaskets"

Different engine mind you, but the problem thresh-hold is 30 mbar (0.43 psi). Not a great deal of pressure.

In cold weather, the moisture that condenses in these vent hoses can freeze. The vent hoses can become completely blocked, allowing pressure to build in the crank-case, especially if your hoses are partially plugged already, or kinked.

Here is a mod to reduce the oil escaping through these hoses, and the oil/water sludge that builds up there:

https://www.audiworld.com/forums/sho....php?t=2792023

hubturn

Moving back to your photo of the brake booster line, your set up is for the manual transmission. The three way valve is for the automatic. I just ordered the three way from Audi and will get it tomorrow. $57. The three way valve has a more involved setup and also connects to the plastic hose running from the head to the noise damper. I comment on this because mine cracked and the idle was terrible. Also, the same valve in your picture is also in my set up BUT, the small hose fitting in the picture is capped with a plastic piece. There is no vacuum hose going to that fitting. I think you should consider that maybe the cap came off and you are losing vacuum through that. Additionally, and not to be irritating, but have you looked for the small silver colored vacuum diagram that may be stuck to the underside of the hood near the drivers side hinge? I would think that would be a specific diagram for your vehicle.