2011 CTT Air Suspension Issue
03-30-2023, 12:33 PM
#31
Track Day
Thread Starter
The struts have 4 places they can leak: the top sealing cover piece that has a nut securing it to the top of the shock shaft; the shock shaft o-ring; the lower o-ring at the bottom of the air bag, and finally, the airbag itself can leak air or even be split so it's a major failure.
If the valve body is not doing its job by keeping the pressure in the strut, the strut pressure will decrease, which makes it drop in height. Reading shock pressures is not very accurate and helpful, I have found.
One of the first steps before testing anything is to be sure you start with a full system, meaning over 110 liters of system volume. If your system volume remains about the same during all the ups and downs (doesn't drop below 100), then your valve block is likely toast. Time for a new one!
If the valve body is not doing its job by keeping the pressure in the strut, the strut pressure will decrease, which makes it drop in height. Reading shock pressures is not very accurate and helpful, I have found.
One of the first steps before testing anything is to be sure you start with a full system, meaning over 110 liters of system volume. If your system volume remains about the same during all the ups and downs (doesn't drop below 100), then your valve block is likely toast. Time for a new one!
05-02-2023, 09:50 PM
#32
Track Day
Thread Starter
Update: Replaced valve body, still having the issue. Did however find corrosion on the fittings after removal. Going to replace the whole right front strut as that lower O-ring is likely leaking and I cannot find the part number for it. Also, I have called around to 4 shops, Porsche North Austin and Porsche South Austin included, and none of them do nitrogen fill!!! I may have to do it myself.
05-06-2023, 09:51 PM
#34
Track Day
Thread Starter
05-16-2023, 08:12 PM
#35
Track Day
Thread Starter
Small update: Shock will be here Friday (5/19/23). I was driving around house shopping with the wife and drove past an Indy shop in east Austin, happened to look in my rear view mirror and see a 981 Cayman and a 955 Cayenne sitting in the parking lot. The sign was too far away to read, so I pulled out Google Maps and found that it was named GT International. I called and spoke to Clayton who told me that they in fact use nitrogen to refill the system! He explained that it takes quite some time to finish the job (2-3hours with recalibration and whatnot). Friday I will be swapping out the shock. Monday I will be dropping the Cayenne off to have it filled back up!
05-16-2023, 09:35 PM
#36
Rennlist Member
Just a heads up, Porsche now allows Grade 5 Nitrogen or oil free compressed air. Most shops will probably now use the compressed air because, well.... Milkshake brings all the boys to the yard. Your Cayenne will require service sooner, especially in cold weather.
05-17-2023, 12:22 AM
#37
Track Day
Thread Starter
Oh that is interesting thanks for the heads up......I am still going to go with the Nitrogen fill haha.
06-16-2023, 01:32 PM
#38
Track Day
Thread Starter
Final update: Replaced right front strut with new. Issue solved. I may send the original strut back to be rebuilt. I wonder which seal went bad, could possibly have been the new one that I replaced or the lower o-ring....who knows.
After confirming the issue was solved, I installed lowering links and got the stance that I like, but man can it be bouncy at low speed. The dampening seems great at higher speeds. I will probably raise the vehicle back up a touch, just to avoid the bounciness. Wheel spacers, downpipe and tune are next. Thank you for all of the help!
After confirming the issue was solved, I installed lowering links and got the stance that I like, but man can it be bouncy at low speed. The dampening seems great at higher speeds. I will probably raise the vehicle back up a touch, just to avoid the bounciness. Wheel spacers, downpipe and tune are next. Thank you for all of the help!
06-16-2023, 11:50 PM
#39
Rennlist Member
Everyone I know who's installed lowering links has removed them.
06-17-2023, 08:17 PM
#40
Track Day
Thread Starter