Hi Everyone,
I'd asked this question in the wrong category earlier, so please pardon me if you'd seen it before.

I just got a 2015 ML63 but not certain how the airmatic system should work;
each time I lock the truck after a drive, its drops an inch or so with a hiss of air. And I do hear a faint whir near the front left wheel for some minutes.
Is this normal function or an indication of something wrong?

Thanks for any advise in advance.

That is normal

Thanks a lot!