Hi, new here today and have searched a lot and found "similar" but not the same issue so apologies if this has been covered a million times before...

I'm looking to the Hive Mind to help me out here with an issue with my 2010 GL550 (GL500 in UK) which recently in the last few weeks has started losing height on right-hand front when it is in normal height, but maintains height across all four wheels if in "off road level 1" or higher. (I'm going to call that ORL1 for ease of typing)

So I'm currently driving it around in ORL1 all the time which is okay, but as soon as I want to use motorways [freeways] I have to limit my speed to 67MPH else it automatically drops back to "normal" height and from there the right front just keeps dropping until it is on the stops.

Is it possible there's a leaky air spring? But why wouldn't that leak *more* at the higher pressure of ORL1?

I've done the usual google/bing searches and whilst there's a lot of chat about leaky air springs *none* of them exhibit the weird symptom I'm describing where it stays up if on ORL1 or higher, but drops if lower than that (and keeps dropping until bottom)

Baffled I am. Some would say bamboozled.

Thanks in advance!

 

This could be due to a malfunctioning height sensor or a faulty air control module that's not maintaining consistent pressure on the right front side. Another possibility is a restricted or leaking air line specific to that corner, which only becomes problematic when not in ORL1 mode because the higher pressure in ORL1 temporarily compensates for the leak. Additionally, the compressor might be struggling to sustain adequate pressure across all channels, leading to uneven suspension behavior.You should probably run a full system scan to pinpoint the exact cause. There should be fault codes on at least one or more control modules related to this issue. Use a full system scanner like Xentry if you have it. I tend to use youcanic full system scanner as it’s easier and quicker for diagnostics. It can run an in-depth all-system scan and diagnostic. If the scan doesn't reveal anything, we might need to dig deeper—and trust me, my toolbox has seen some interesting things!

 

Actually, what you describe is quite normal and happens quite a bit. It's simply due to how the bag folds in the lifted vs normal position in that when it's folded just right, it "plugs" the small hole. Don't worry - it will get worse And probably at the most inopportune time. There's plenty of threads here on this forum about if you want to search - but that's the jist of it.

You said you did a bunch of searches about this... I'm sure you came across easy ways to check for the leak by either listening or spraying soapy water on the bags. Have you done that?

For good measure, have you removed the height sensor connecting arms and made sure the lever moves freely and then clean/grease the ball joints (or at least clean)?

 

1,000,001 times now.

 

This is quite normal. Failure modes aren’t exactly always straightforward and that it only leaks all the time… Sometimes it only leaks when the bag is in a certain position.

Put some leak detector spray or soapy water on that bag and you will see bubbles.

 

Mine did the same thing where if I could get it to the lifted position it would often stay there. It just depends on where the actual leak is on the bag and if it's being folded over on that leak depending on the height. Replacing the bag and strut assembly fixed it.

 

Thanks all contributing, as predicted above its now failed more spectacularly and the right rear has dropped.

Will bite the bullet and replace all four corners this weekend...

Wish me luck