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Brave soul you are. I've had enough fitment/quality issues with Chinese crap to where I would never trust a $80 piece of garbage to carry me down the road. You would be amazed at ways they find to cut corners to save pennies, even within the same factory.
The control module will equalize them, that's how. The sucker periodically wakes up and checks... I guess same reason you're supposed to put the suspension in service mode before lifting the car, or the control box will start adjusting as you lift the car up even with key out of ignition.
If you want to test which side on the axle is leaking:
1. Measure ride height on each side from center of the wheel to the top of the arch.
2. Disconnect the control module.
3. Measure ride height after a couple of hours/days. The side that sagged more is the one with the leak.
Regardless, unless your car drops completely to the ground, the issue is not with the air bag itself. Residual pressure valve seems somewhat common failure point, as I've seen a number of threads for both Cayenne and AS equipped Touaregs on this. The valve frequently disintegrates when you attempt to remove it.
The car does drop to the point where there would be zero pressure in the rear. This car sat for 3 years, and when I got it there was of course no air in the system. It took quite a while for the system to work itself out, etc. The AS leakdown has also gotten worse over time (it used to take about 3 days to leak down)
Originally Posted by J'sWorld
I am sure your time is worth something. While you have some valid points on parts producers the difference is who the part manufacturer is selling them to and the spec it has to meet to satisfy that client and their quality/financial needs. The car doesn't have to be an experiment as they are proven great vehicles. Sounds like you are comfortable working on them and that's a big thing. Over the years I have seen the few instances of collateral damage from a reproduction wheel breaking or an airbag blowing while driving and it ain't pretty. If you didn't drive the PIG for what it's worth then you wouldn't have gotten one. I drive 100 whenever I can, I think that's a given.
Still I would be willing to bet on my limited knowledge that the bags are not the problem. You could always try some soapy water spray? Each strut has a dedicated air line that runs from the strut to the valve block. I don't see how both rear could bleed evenly without going through the valve block first. A lot of people misunderstand the purpose of the residual pressure valve at the top of the strut. It is not a check valve or one way valve. It simply flows both ways until the pressure on the strut side drops to a specific psi and will not let any more escape after that. I think it's around 2 bar. This is so the bag doesnt deflate completely because it can damage the bellows inside and still allows you to roll around with a fault. This is why the struts come from the factory pre-charged and strapped in a mid-extension position. A lot of thought went into this air ride system and compared to all the other big auto manufacturers I agree its really good if not one of the best. The only other leakage point at the strut is the o-ring at the top. I would find it hard to believe that both rears are leaking evenly at those two o-rings. Just some ideas for you.
I agree it could be something else. I'm going to put it on the lift and see what the deal is, not just default to throwing in the 40 dollar struts hahaha. Worst case, the struts are garbage and I let the forum know so we can have a laugh at my $80 expense. Best case, they are very nice and work fine. Middle case, I steal a few air parts off of them (o ring, bag, etc). Like I said, I dont trust that the bags/o rings *dont* have damage - the car was dropped flat with no air for 3 years....
Just measured the car - after driving for 25 minutes, the car in the "low" position. The driver side and passenger side were already off by almost an inch (which doesnt seem right? Is the adaptation off?), right after shutting off the engine. The passenger side was lower, and after about an hour of sitting, the system dropped about another inch. The passenger side definitely lost air more quickly, but both sides certainly were dropping way too rapidly. I cannot hear any air escaping.
Ok so I dont want to be *that guy* but I found this..... I can get both rear *strut assemblies* for $100 shipped. Seems kinda crazy but it looks like they were discounted from ~$500. Clearing stock?
Honestly, for $100 I might roll the dice lol. Worst case I just steal the air parts... Still cheaper.
-Will
Wow! $43 for a whole air strut assembly?! Normally i'm very skeptical of deals like this, but Porsche charges more than $50 just for the seals and accordion dust covers. Worst case, if the new air struts seem like crap, you can still use the dust cover and seals to rebuild your old ones and still be ahead. Thanks for the link, I ordered two struts just for giggles and it set me back all of $86! There was another site asking over $500 per strut for the same part number as these so I don't know if they are discontinuing these or if a noob staff member may have fat fingered an extra digit when they marked them down. These will either be the deal of the century or a lawsuit waiting to happen. For $86 bucks, it's worth it just for the entertainment value alone.
Last edited by DIYDanCars; 03-12-2019 at 03:33 PM.
My rear air springs were leaking at the upper o-ring due to corrosion. I removed the airsprings and sanded away the corrosion and used new o-rings. Lots of silicon grease too. Airbags themselves looked in great shape. $10 per side. pics are out of order, but you’ll get the point. No cheap Chinese parts either.
Those are the original shocks. '04 CTT, 170K miles. I've done all four corners and only the rear had corrosion. Replace upper and lower o-rings. Use Porsche O-rings, and silicon grease (or dialectric grease) as it is compatible with the o-rings.
Wow! $43 for a whole air strut assembly?! Normally i'm very skeptical of deals like this, but Porsche charges more than $50 just for the seals and accordion dust covers. Worst case, if the new air struts seem like crap, you can still use the dust cover and seals to rebuild your old ones and still be ahead. Thanks for the link, I ordered two struts just for giggles and it set me back all of $86! There was another site asking over $500 per strut for the same part number as these so I don't know if they are discontinuing these or if a noob staff member may have fat fingered an extra digit when they marked them down. These will either be the deal of the century or a lawsuit waiting to happen. For $86 bucks, it's worth it just for the entertainment value alone.
Bingo, exactly! It'll be a laugh worst case - It's like an episode of Hoovies garage if it works out or not "I fixed my 100k Porsche for $80". It is such an oddity that I may end up with a good part, a bad part, or an empty box that says "Porsche Air Strut" in the finest chinglish possible. The mind boggles...
They supposedly shipped, I'll keep you guys posted!
My rear air springs were leaking at the upper o-ring due to corrosion. I removed the airsprings and sanded away the corrosion and used new o-rings. Lots of silicon grease too. Airbags themselves looked in great shape. $10 per side. pics are out of order, but you’ll get the point. No cheap Chinese parts either.
Originally Posted by J'sWorld
@ Jagman, how much of a difference did the new shocks make?
Originally Posted by JAGMAN1
Those are the original shocks. '04 CTT, 170K miles. I've done all four corners and only the rear had corrosion. Replace upper and lower o-rings. Use Porsche O-rings, and silicon grease (or dialectric grease) as it is compatible with the o-rings.
Thank you for the pictures and ideas! I totally agree it may be/probably is just the O rings/corrosion. At 170k miles my car is basically the same miles, and if your struts were ok (no leaking, etc) then I'm tempted to go the same route. Do you have the part numbers for the OEM O rings (top and bottom)? I guess I could just dissasemble the chinesium shocks and steal those o rings too. Maybe even the entire top mount? For $80 who cares what happens. Considering a gallon of porsche coolant is $60 lol
The Chinese parts are intriguing indeed. But sometimes the biggest weak points of those parts is the rubber. The o-rings in particular. If you were to go to Home Depot and buy an o-ring it would dry rot within a year. Whereas the ones I took out were still ok. Not great, but not cracked. Buy the Porsche o-rings and you'll get another 15 years out of them. Part numbers to follow.
My 15 year old o-rings on the 04 were still nice too. Crushed a little maybe. I used a thin smearing of copper silicone on surfaces and old o-rings and all was good.
What he said. Silicon May work on the uppers, but I believe there is som rotation of the lower sleeve over the o-ring up front. So grease may be better suited there.
In the end my leak was caused by corrosion on the aluminum hat and groove. I sanded it smooth with a dermal.
All in all I replaced upper and lower o-rings and upper bushings at all four corners. I did a little paint touch up on the shock too. <$100 total. I have no intention of doing that job again. Not that it was too hard.
Mine will be here Friday and appear to be coming from Canada. I did some research on the company and buyers seem to be pretty pleased with their products for the most part -- most are rated 4 stars or higher.
The Chinese parts are intriguing indeed. But sometimes the biggest weak points of those parts is the rubber. The o-rings in particular. If you were to go to Home Depot and buy an o-ring it would dry rot within a year. Whereas the ones I took out were still ok. Not great, but not cracked. Buy the Porsche o-rings and you'll get another 15 years out of them. Part numbers to follow.
The rubber nowadays from *any* manufacturer is of question. Tires barely last a few years, rubber seals last only a few years, etc. I have tires on tractors from the 1960s that are still good. Crazy...
Originally Posted by J'sWorld
My 15 year old o-rings on the 04 were still nice too. Crushed a little maybe. I used a thin smearing of copper silicone on surfaces and old o-rings and all was good.
Good call - maybe just cleaning, removing corrosion and lubrication would help correct the issue.
Originally Posted by JAGMAN1
What he said. Silicon May work on the uppers, but I believe there is som rotation of the lower sleeve over the o-ring up front. So grease may be better suited there.
In the end my leak was caused by corrosion on the aluminum hat and groove. I sanded it smooth with a dermal.
All in all I replaced upper and lower o-rings and upper bushings at all four corners. I did a little paint touch up on the shock too. <$100 total. I have no intention of doing that job again. Not that it was too hard.
I purchased the parts from Sunset.
I'm looking forward to digging into this project! I'll take some pictures....
Originally Posted by Dan87951
Mine will be here Friday and appear to be coming from Canada. I did some research on the company and buyers seem to be pretty pleased with their products for the most part -- most are rated 4 stars or higher.
This was my finding as well. My struts actually came in but I havent opened the box! Will report back with my findings lol
Looks like my suspicion was right. Both the eBay and Amazon seller have raised their prices back up to $260 for the air struts. If I had to guess... a noob staff member added an extra digit to the discount code. Hope a few of you were able to take advantage of their mistake.
Looks like my suspicion was right. Both the eBay and Amazon seller have raised their prices back up to $260 for the air struts. If I had to guess... a noob staff member added an extra digit to the discount code. Hope a few of you were able to take advantage of their mistake.
Hahahaha!! Classic. Maybe I got a good part afterall.... We will see later today when I get home.
03-12-2019, 09:25 AM
Classic. Maybe I got a good part afterall.... We will see later today when I get home.