AKN Vacuum Lines: Installation & Maintenance

Hello colleagues,

Sure, here's the translation:

"Once again, I have two questions."

1) The control valves (e.g., N75, AGR) are connected to the air filter housing, which has an external pressure tap. If there is a leak at that point, will this leak affect the control behavior?

I want to replace all the vacuum hoses now. If I also replace the high-pressure hoses (where I don't anticipate any problems), it will be extra expensive. If the length and diameter of the high-pressure lines significantly affect performance, I will replace those as well. However, if the lines are only there to prevent dirt from entering the system, I can probably skip that.

2) What's the easiest way to access the spare tire? It's located near the front left wheel, but what needs to be removed? The bumper, the inner wheel arch liner (front or rear)?

I know how the discoloration works, but I didn't get an answer to my question in the forum. I also know that the vacuum is an important factor (which is why I made the change).

Thank you for your answers!

Tom.

Hi Tom,

Unfortunately, I can only help with point 1. Regarding the valves, you could just leave the connections for ambient pressure open without using a hose.
They are connected to the air filter housing only to prevent dirt from being drawn into the vacuum system.

The only difference in operating behavior would likely occur with a severely clogged air filter, in which case there would be no "ambient pressure" where the hoses are connected when accelerating.

Best regards, Rainer.

Hello Rainer,
Okay, that's helpful. I'll just skip replacing the ambient pressure lines. That should save us at least 2 meters of tubing.

Interestingly, VW seems to be focusing on costs, but this approach seems inconsistent to me. Wouldn't it be cheaper to integrate simple mini-filters directly into the control valve, rather than using the current design? That's why I'm asking.

Now for the second question, and then I can start my weekend. If no one knows for sure, it's not so bad; I'll just keep searching until I find it...

Tom.

Herr Antje wrote:

Hello Rainer, Okay, that's helpful. I'll just skip replacing the ambient pressure lines now. That should save us at least 2 meters of tubing. Interestingly, VW seems to be focusing on costs, but this approach seems inconsistent to me. Wouldn't it be cheaper to integrate simple microfilters directly into the control valve, rather than using the current design? That's why I'm asking.

Hi,

Regarding the valves: I have these valves without pressure relief ports, and they have small foam filters on the actuators. I personally only experienced the usual problems with one of the valves malfunctioning (the control nozzle was clogged, and the vacuum was no longer properly generated after the valve), but this was due to a leak in the line leading to the pneumatic capsule.
"Indeed, there are occasionally problems with the filters clogging. In my case, they are also located on the oil pan, and using too much brake cleaner after an oil change can cause the foam filter element to disintegrate. If used properly, there are no problems. Perhaps the difference with and without the hoses is also related to the fact that the intended space for the valves may not be sufficiently free from dust, spray, and jet water."
By the way, these are also Pierburg products, and they look exactly the same as the ones without a filter (they cost 32€ at Pug).

There really isn't much space at the AKN. You'll probably have to remove the wheel arch liner.

christians wrote:

There really isn't much space at the AKN. You'll probably have to loosen the wheel arch liner.

"So, you mean I have to get to the memory module now, right? Where exactly is it? Is it behind the wheel, above it, or in the front near the windshield washer reservoir? You can't really see anything, just a (1) disappearing hose..."

I suspect it's located at the front, above the wheel. I've opened it up a few times before, but I've never paid attention to it.

Thank you, Christians. I was looking for my windshield washer fluid reservoir a few weeks ago, but I couldn't find it. If it turns up for me sometime, I'll let you know .