Turbo Actuator/N75 Hose Routing - Help Please

I have been looking through some pics and have made the following conclusion for the connections on the N75 valve. Can somebody verify if they are correct, and if not, how I should re-label.






Also, I am guessing this is the vauum source. Am I right?





thanks

IIRC the top one goes to the actuator, its the output

If you look closely at the N75 top, you'll see labels next to the nipples.

"IN" is the vacuum source. You have identified it correctly. That small hose next to the red-capped hose is the connection. Those loops around past the air filter box (there's a check valve in it along the way), through a clip on the air filter box facing towards the front of the car, and down to the N75. Shortly before the N75, there's a T fitting with a short hose going to the vacuum reservoir ball, right there in the background of the picture (half covered with heat shielding).

"To Turbo Actuator" is correctly labeled. It just snakes up and onto the nipple of the actuator. N75 label is "OUT".

The remaining "To Turbo Inlet" hose snakes up through that same clip and to a nipple on the air filter box lid, on the side of the lid facing the rear of the car. It should be called "fresh air inlet".

Thanks for the additional info MOGolf.
Do you have a part number on the check valve?

That would be 046 905 291 A.

And if you want to be "part correct" the Y fitting (referred to as a T fitting above) is 056 129 971. I'm sure no one would notice a suitable substitute.

A significant length (620 mm) of the tubing from the check valve to the N75 is actually rigid pipe. N 020 139 1.

thanks MOGolf.

Hi, i have a question on my car which is a 1998tdi auto there seems to be two of these valves on my car one at the back on the black plastic pipe (induction pipe i think) and one at the front of the car where your picture shows could anyone tell me what the one at the back is for ? as i am also expereancing intermitant power loss i have checked the vacuum pipes they all seem fine thanks pete. the part numbers on both valves are as follow 1HW90662722/29 7.21903.6098T148 and the second one is 1HO 906527A22/98 7.21905.2598T149

MOGolf said:

The remaining "To Turbo Inlet" hose snakes up through that same clip and to a nipple on the air filter box lid, on the side of the lid facing the rear of the car. It should be called "fresh air inlet".

Click to expand...

Do you know if it goes to the fresh air side of the filter or the engine side of the filter, I am just trying to sort this out for my jet boat and I do not have a stock air box so I'm just curious as to the importance of it going to the air box

Filtered of course. You don't want dirty air going anywhere into the engine or its controls.