I may be wrong so it will need others to confirm one way or t'other, but I thought there was a condenser/drier in the system somewhere?

 

From SSP 469

"The air for the compressor is supplied via the air filter in the engine compartment. The air is drawn in and cleaned via the silencer/filter. The air is released via a separate line."

"The air supply unit consists of:
- the compressor unit with electric motor, compressor, air drier, silencer with air filter, pneumatic release valve with maximum pressure limitation (pressure limiting valve),
- the solenoid valve block with the control valves for each air spring damper and the solenoid release valve."

"The system (air suspension system) is refilled in service with nitrogen using the connection provided on the pressure accumulator."

So, it has a drier and use ambient air after the nitrogen gets lost. Need to take a dive into ElsaWin and see if it can be replaced or dried.

From ElsaWin:

"Compressor - Cannot be repaired"

And thats all ElsaWin will tell me about the compressor.

ETKA and google next.

Part Number for the compressor is: 7P0 698 007 B

 

The original compressor has rebuild kits available. The typical problem is the ring around the piston needs replacement. Most kits sell the dryer kit bundled with the ring repair kit, but you can get a dryer kit separate.

Note: I don't know if this kit will fit a 2011, but it is a start. It appears to have two felt air filters and the dryer beads.


www.amazon.com/SUSPENSION-COMPRESSOR-FILTRATION-45-FILTER/dp/B06XH4FHMP

 

Thank you for the link nickyt. I am considering buying two of these sets, and have some filt at hand in case the diameter is larger.

 

The T3 system is closed, it normally should never have to draw in outside air. The reservoir and air bags are charged with dry nitrogen. The only time your system would be drawing in outside air (oxygen) would be if you had a leak.

 

According to SSP 469 a temperature difference can make the system fill with air as well.

"The pressure accumulator is filled if the pressure in the system has changed due to leaks or temperature differences. If the pressure in the system rises above a certain value due to an increase in temperature, the air is released to the outside. The pressure accumulator capacity is 6.2 litre"

And we have had a difference of at least 65 degrees C the last year. But the need to refill should happen at the lower end of the scale where the actual water content in the air should be low, but not low enough.

Is there a way to tell if the system is refilling? Haven't noticed any dropped corners nor excessive use of the compressor.

 

You can view the status of the complete air system with VCDS. You can view individual bag pressure, reservoir pressure, and standby pressure. IIRC, the reservoir is charged around 180-200psi, which is much higher than the bags will ever have in them. The compressor is only capable of perhaps 130psi max. If VCDS says your pressures are under 140-ish, you have a leak. Therefore, if you have your compressor drawing in outside air, you have a leak.

If it were my vehicle and I lived in a cold climate such that you do, I would have the dealer completely drain and re-charge the system with dry nitrogen. Moisture WILL kill the air suspension system. You can also charge the system yourself with a dry nitrogen tank, pressure gauge and valve, and the T10157/1 adapter tool (this is what I did).

 

I did just check, 10.2 bar in the accumulator. Which is about 140 PSI. So I am down on pressure.

But how does this work? If the Accumulator is 200 PSI, and any use of that pressure will be lost as nothing can get it high enough not refill the accumulator. It's a backup of sorts then? Or designed to slowly be used up until next service?

 

Hopefully someone knows the answer to iSagen's above questions. I will throw in another thought which might be helpful.

So, are there any dryer beads in the later gen air suspension?

If so, it would be good to replace them with fresh before recharging with nitrogen. An old trick, if you can not get new Desiccant is to dry the old Desiccant in an oven at about 210 degrees.


Also, here are a few links in case someone is not already knowedgeable in desiccants.

dryingbeads.org/?page_id=72

Drying beads® ... The beads will continue to absorb water until all of their pores are filled, up to 20 to 25% of their initial weight. ... ... ...The beads can subsequently be removed and regenerated separately by heating at >200°C for 3-4 hours to release the absorbed water.

theworkshopcompressor.com/learn/compressed-air-systems/compressed-air-dryer/desiccant-compressed-air-dryer/

 

@chewblekka, can you make a stept by step tutorial on how to bleed/refill the tank with nitrogen? Maybe its good to do this once a year, just as a precaution.

 

ODIS has a guided function for this. I will use this once I can find an adapter.

The guided functions of ODIS is gold, the software walks you trough a lot of fault searching and resolves problems as well in participation with the user. It asks the user to check things the software cannot do with clear instructions where to find the part to be checked and what to look/hear for.

It also includes guided functions for things like bleeding and filling the air suspension system.

 

ODIS has a guided function for this. I will use this once I can find an adapter.

Any updates?
I have this, accumulator pressure 6.8 bar

 

What happens if you take a drive? Will the compressor pump it up to approx. 10 bars?

 

No, not really, it was working but not pumping more than 10 bars into the tank. I found a leak but it was loosing air veeeeeery slowly. After 1 week of sitting, car was still leveled. It was leaking only if it was in extra offroad, and in 5 minutes the rear left was sagged. In Normal mode, it was driveable but the compressor was almost always on.
Yesterday i fixed the rear left bag and the new values are:

Now im testing to see if the problem is fixed and after i will fill the sistem with Nitrogen.

 

No, not really, it was working but not pumping more than 10 bars into the tank. I found a leak but its loosing air veeeeeery slowly. After 1 week of sitting, car is still level. It leaks only if i put it in extra offroad.
Yesterday i fixed the rear left bag and the new values are:

Now im testing to see if the problem is fixed and after i will fill the sistem with Nitrogen.

That look right. The pump cannot create more than 10 bars, and left/right side is equal. All should be OK now.

 

For those who need the PNs for fixing and filling with N2:

Tools:
-T10157
-V03839037QA
-VAS 6629
-3186 (21mm socket)

Strut repair kit:
-7P6412327 or (Lemforder 3977001)
-7P0412269A
-N90367701
-7P0616045
-7L0616817 (valve o-ring)
-Febi 31942 (Lithium vaseline)

 

Nice progress!
Was it a big job fixing the bag?
Same parts are probably used in all 4 bags?

My problem is the car lowers equally much all around so nothing pointing to a specific bag.

 

Now that I left it in offroad extra it seems the rear right side corner is lower when left sitting a while. So would probably be a good place to start.

 

My garage visit was ruined when I found out that the 7P compressor sold to me was 7L compressor and one electric connector don't fit and little bit fidling with air pipes aren't enought.
Trying to find fast solution to get back to road without paying 1700€/2000$ dealer price for compressor and rageing around with google I stumbled to 7P style kit of cylinder, piston and connecting rod for about 50$ so if compressor isn't totally ruined they can be also fixed.
My old comp was very lazy on table with no back pressure compared to new L7 in same situation. Bigger L7 comp with big see through silica container and tyre filling pipe could be nice upgrade to my car as it's the more "offroad" 4x modell with central and rear locks and central reducing diff.

 

Guys, I have a 2011 7p and when temperature gows under -5 my air compressor freezes and blow my fuse (I can here it trying to start, he strugles a bit, than the fuse blows). My mechanic said that the dryer filter inside the compressor is gone and I should replace the compressor. Is this accurate information?
Also, my car sits down over night and in the morning when I open the door it levels back up (if its not freezing temperature outside). Does this mean I have a leack?

 

Yes, you have a leak and you need a new condensor.

Read this thread:

Condensation in air suspension freezing.

Does anyone else get blocked valves and blown fuses when the temperature drops below -12 C? I asked my dealer to flush the system with nitrogen, which they at first refused to do. After some discussion they agreed to do so, at least they said they flushed it. I am suspecting they just topped...

www.clubtouareg.com

Well, goodness me, this very thread to which I am posting IS that thread!!

 

Condensor? or compressor?
I have read the thread but still dont know what to do. Regarding the leak, I have taken the car to the official retailer to test the whole system and they said there is no leak and car going down it’s normal.

 

I still have the same problem, had to use a hair dryer to move the car after a weekend with freezing temps.

For the 7L there is a lot of info on changing the drying beads, but I can't remember seeing anything for the 7P.

Each time i change a bag, a new leak seems to develop in the old bags.

HerrDoc. You need to fix your leak, flush with nitrogen and fix the compressor, either a new one or find a way to replace any drying filter/beads. My oem service rep could not find my leaks either, but they were there. Park in extra high, lock suspension and measure all corners of the car. Next day, measure again before starting up. If a corner drops more than the others, you have a leak. But you need to lock the suspension for this to work.

 

As I saw by now (whitout measurments), it gows down the same in all 4 corners, but I will do as you said. Also, even if I locked the suspension and took the fuse out at night, the car still goes down by morning

 

The condenser is there to remove moisture in the system to stop it freezing.

And find a new mechanic.

You know it's not normal for the suspersion to drop overnight!

 

Ok, but the condensor/air drier cannot be replaced seperatly, right? So I need to fix the leak and get a new whole compressor

 

As far as I am aware the 7P air suspension system has no drier but I may be wrong. The system is filled with dry nitrogen which the compessor recycles to adjust the supension. Nothing is vented and no air drawn in during normal operation. If the pressure in the reservoir falls to low due to a leak then I believe the compressor can draw in fresh air and thus it may introduce moisture into the system leading to freezing. There may be a drier system on this air intake but if it exists it has no regeneration ability so would only last for a short time until the leak could be fixed and the system recharged with dry nitrogen.

The 7L system as i understand it vented and drew in fresh air continually rather than recycled it and the dryer system was a two way flow with the dry air when it vents regenerating the drier beads which then absorbed moisture when the system draws in air.

 

So if the circuit in 7p is a closed one and there is no air inflow from outside, than fixing the leak and introducing nitrogen will solve the problem. A confirmation would be much appreciated. Thank you all

 

“The air supply unit is mounted at the front right as a compact unit on the underbody. It is protected from dirt by a plastic cover with ventilation holes. The air for the compressor is supplied via the air filter in the engine compartment. The air is drawn in and cleaned via the silencer/filter. The air is released via a separate line”

Found it in a WV service training…so it seems like air it is taken from outside

 

I dont know where you found this information but it sounds like the 7L system. SSP 469 describes the closed loop system. On rereading it , it does show an airdrier in the system for if and when it draws in fresh air due to leaks but as i said this will be used rapidly as it has no regenration system like in the 7L if leaks are present for any extended period. You need to make sure no leaks , recharge the system with dry nitrogen and potentially replace or regenerate the air drier if thats possible without replacing the whole compressor unit which is very expensive