GL Class (X164) 2007-2012: GL320CDI, GL420CDI, GL450, GL550

Both Rear Air Shocks Flat

Old Jun 10, 2022 | 06:48 PM
  #1  
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Both Rear Air Shocks Flat

Today my wife was driving her 2012 GL350 and thought she heard a “pop” and looked to see if she ran over something on the road but she didn’t see anything. My wife continued to a local store and while loading groceries she noticed the rear end was lower than normal. On her way home she could feel that all the air was out of both rear shocks and was causing the rear of her vehicle to bounce dramatically! I replaced the air compressor with a new Arnott P-3277 air compressor 02/2022 and the rear shocks were replaced with Arnott air shocks in 2019.
Any ideas?
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Old Jun 10, 2022 | 08:07 PM
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NGL450 w/EORP, S550
Nah man pretty straightforward.
Find the leak, if you’re lucky it’s the rear bags and it’ll be obvious where the hole is.

hopefully it’s not a burst line or a valve block and you’ll just swap out the bags under warranty.

Last edited by Max Blast; Jun 10, 2022 at 08:12 PM.
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Old Jun 10, 2022 | 09:07 PM
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I bought the rear air bags from Arnott on 05/16/2019 and may be out of their limited 2 year/limited lifetime warranty. It seems odd that both bags would flattened at the same time which leads me to believe it’s an air hose that may have popped out from the new air compressor. Would one broken air line cause both air bags to flatten?
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Old Jun 10, 2022 | 09:29 PM
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NGL450 w/EORP, S550
Originally Posted by KYBRIGGS82
I bought the rear air bags from Arnott on 05/16/2019 and may be out of their limited 2 year/limited lifetime warranty. It seems odd that both bags would flattened at the same time which leads me to believe it’s an air hose that may have popped out from the new air compressor. Would one broken air line cause both air bags to flatten?
The car will try to level itself so one bag leaking will cause the other side to try and adjust.

Hence my comment that hopefully this just a blown bag - but get some leak spray and go looking.

There is one input line from the compressor to the valve block, if that blew all four corners would be down.

each rear bag has a dedicated line from the valve block so not likely that both lines have popped.

if not one or both bags, then the next suspect is valve block internal failure.

whatchoo talkin bout Arnott limited life warranty? Thought it was for life.
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Old Jun 10, 2022 | 10:22 PM
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Thanks.. I’ll check Monday and advise!
What are the symptoms of a valve block failure?

Arnott Inc.® offers a Limited Lifetime Warranty for North American customers on Arnott Air Springs, Air Struts, Compressors, Coil Spring Conversion Kits, Valve Blocks and Arnott Adjustable Motorcycle Suspension Kits. Orders for Arnott products outside of North America, including the European Union, come with a Limited Two-Year Warranty.

Here I thought Arnott had a real lifetime warranty but I see that’s not the case! I guess parts are just parts!

Last edited by KYBRIGGS82; Jun 10, 2022 at 10:29 PM.
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Old Jun 10, 2022 | 11:00 PM
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NGL450 w/EORP, S550
Originally Posted by KYBRIGGS82
Thanks.. I’ll check Monday and advise!
What are the symptoms of a valve block failure?

Arnott Inc.® offers a Limited Lifetime Warranty for North American customers on Arnott Air Springs, Air Struts, Compressors, Coil Spring Conversion Kits, Valve Blocks and Arnott Adjustable Motorcycle Suspension Kits. Orders for Arnott products outside of North America, including the European Union, come with a Limited Two-Year Warranty.

Here I thought Arnott had a real lifetime warranty but I see that’s not the case! I guess parts are just parts!
Lessn ya moved to Greenland you’re good.

Last edited by Max Blast; Jun 10, 2022 at 11:02 PM.
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Old Jun 10, 2022 | 11:57 PM
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Well Sir, I stand corrected! Thanks I’m hopeful now!
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Old Jun 12, 2022 | 01:07 PM
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Funny how so few failure reports here regarding Bilstein or OE Mercedes air springs. Always Arnott.
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Old Jun 12, 2022 | 01:28 PM
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I think if I discover it’s a valve block issue then I’ll buy OEM Mercedes. If it’s the 4 month old Arnott air compressor then I return the air compressor back to CarID under warranty BUT unfortunately CarID is out of stock, so I hope I can work directly with Arnott. Last but not least if it’s the Arnott rear air bags I bought on Amazon then I’ll send it back under warranty.
Maybe OEM from now on is my best avenue for future problems.
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Old Jun 13, 2022 | 12:54 PM
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Issue solve!
My 4 month old Arnott air compressor air hose disconnected which caused all (4) air bags to lose air. My mechanic pushed in the air hose back into the air compressor and the system filled up to normal levels.
My mechanic said he notice a small amount of oil that sprayed in the area where the hose disconnect but was unsure how much was lost.
Anyway a cheap day for my wife’s SUV!
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Old Jun 13, 2022 | 11:19 PM
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That is a different problem than was presented but glad you found a solution.
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