Hello everyone,

I've just changed my front air shocks: the front one was almost touching the ground after 4 hours, when car is stopped, but was obviously coming back up with the engine running.
However, I've just replaced my 2 front shock absorbers - not Genuine but from an OEM reputed for these components in Europe on German cars.
After fitting (no leaks identified), I notice that the car is dropping slightly from the front over the days: about 5mm per day, but it's very variable - sometimes 1cm, sometimes nothing ( or 1-2mm)
The car is locked, so it's not supposed to adjust automatically.

All the more strange that if I open the car, get in and out (without starting it), lock it and the suspension recalibrates automatically: the car goes back up (probably thanks to the residual pressure in the attached tank).
I'd like your opinion: so far, it's never sagged, but after 4-5 days it seems to be quite low.

For the rear, there is no change in height, so everything seems normal.


Any ideas?
Call to the shock absorber manufacturer's after-sales service: micro-leak.
Calibration problem? Sensors ?
Normal? I've never seen this before, or maybe I just wasn't paying attention.

Thanks in advance for your feedback

 

so after few days the drop is 1cm or 5cm? if 1 - i would not care, if 5 then have you verified if there are not leaks on the lines or the distribution box near compressor?
you dont need to start engine to get the suspension pumped, when you wake up car (by clicking open on fob, or by opening the door by your hand) the adjustments are done.
i dont see here callibration issues or sensor issues... its a leak somewhere else than strut (if you are sure strut is not leaking) or you may overreacting 1cm of drop after few days.

 

Hello @redstr3842 ,
Have you checked at the top of both new struts with soapy water for air leaks ?

Here are some pictures showing the area in question, notice the brand new shiny strut blowing bubbles at the top...

You should also spray the lower portion of the struts at the bottom of the accordion boot.

Johnny

.

 

Hi,
The difficulty is that the variation is not constant. Between yesterday and today, for example, I've just checked and there's a 5mm difference - bearing in mind that just yesterday I had the suspension raised by unlocking and relocking the car: At least the attached tank isn't leaking itself....
Now I'll have to push the tests over 2 weeks to see if it won't completely crush.
In the past, long before the replacement, I'd never paid any attention, measured - I'd only noticed that indeed the front was always lower than the rear.

But the strangest thing is that there's no constant in this drop : Sometime 1cm , 5mm, 2mm,....
I'm going to do a new test by locking the chassis (and removing the fuse) to eliminate the electronic, automatic adjustment cause.

 

Hi,

It's also a point to be checked.
Certainly new shocks, but perhaps a defect.

 

@redstr3842 ,
No need to remove the fuse, put the vehicle in lift mode, then jack mode, and wait to see which corner starts to drop first.

Johnny

 

Redstr3842
Just out of curiosity, who made the new shock you used? Just asking since you are in Europe and might have other options to consider. I know when I was looking at replacing mine I tried a number of German sites for options, but wasn't sure which were high quality or not in a couple of instance.

 

Hi,
Good point Mars911 !
Sold by Aerosus ( Germany) - In fact, my mechanic ( a Porsche and other Luxury/sport cars specialist) recommended that I go through them.
The quality of the products seemed quite serious, as did the packaging and protection (often a sign of provenance...).
Nowadays, it's very difficult to judge the quality of a product by its brand...or its origin. Today, most equipment manufacturers (Bosch, for example, the biggest) manufacture in China...
For purchased shock absorbers, the assembly and internal cartridge are supposed to be made in Germany, but ....

Now, to come back to the leak, I'm doing a new test over a week with the chassis locked ("lock raise" mode) and ...for the last 2 days the car hasn't gone down 1mm - For the moment I'm tempted to conclude that the automatic adjustment sometimes triggers abnormally when the vehicle is stationary. 4 more days for a more precise conclusion.

 

My GT was very sensitive to slope when parked. My drive has a very slight incline from front to rear and the overnight the suspension heights at each wheel were not 100% consistent and always dropped slightly more on the front driver's side (RHD). Not a leak as it seemed to settle at the height and then not change over a day or two. Had it checked several times by a specialist and concluded that it was to do with parking on a non-level surface and the inner workings of the suspension when the ignition was off. It was slightly strange but I had the GT for 3.5 years and never any issues with it getting better or worse. YMMV.

A

 

Hello,
After 1 week without driving (and "locked jack" mode), I noticed a drop of about 7mm on the 2 fronts (replaced shocks) and 0mm on 2 rears (original shocks).
Insofar as the compensation system was locked, I conclude that it's a micro-leak.
Admittedly, it's not too serious...but I'm going to keep checking regularly; the shocks are guaranteed for 2 years.