Air suspension deflating again after spring replacement
08-21-2015, 06:47 PM
#1
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2007 GL450
Air suspension deflating again after spring replacement
2007 GL450. Current mileage: 115K
I replaced the front air springs with Arnott at 57K (early 2011), and the rear at 90K.
The front has begun settling down overnight.
Is there a likely culprit, a reasonable course of testing? Leakage in the compressor? I could squirt soapy water on the air springs themselves, but given the Arnott springs' supposed better life, they don't seem likely to be the cause.
The compressor seems to function normally. In fact, the air reserve is solid, because if I open a car door, I can hear and see the suspension resetting, without the compressor going on (at least as far as I can tell).
Any suggestions on where to look?
I replaced the front air springs with Arnott at 57K (early 2011), and the rear at 90K.
The front has begun settling down overnight.
Is there a likely culprit, a reasonable course of testing? Leakage in the compressor? I could squirt soapy water on the air springs themselves, but given the Arnott springs' supposed better life, they don't seem likely to be the cause.
The compressor seems to function normally. In fact, the air reserve is solid, because if I open a car door, I can hear and see the suspension resetting, without the compressor going on (at least as far as I can tell).
Any suggestions on where to look?
08-21-2015, 10:33 PM
#2
2007 GL450. Current mileage: 115K
I replaced the front air springs with Arnott at 57K (early 2011), and the rear at 90K.
The front has begun settling down overnight.
Is there a likely culprit, a reasonable course of testing? Leakage in the compressor? I could squirt soapy water on the air springs themselves, but given the Arnott springs' supposed better life, they don't seem likely to be the cause.
The compressor seems to function normally. In fact, the air reserve is solid, because if I open a car door, I can hear and see the suspension resetting, without the compressor going on (at least as far as I can tell).
Any suggestions on where to look?
I replaced the front air springs with Arnott at 57K (early 2011), and the rear at 90K.
The front has begun settling down overnight.
Is there a likely culprit, a reasonable course of testing? Leakage in the compressor? I could squirt soapy water on the air springs themselves, but given the Arnott springs' supposed better life, they don't seem likely to be the cause.
The compressor seems to function normally. In fact, the air reserve is solid, because if I open a car door, I can hear and see the suspension resetting, without the compressor going on (at least as far as I can tell).
Any suggestions on where to look?
If both sides go equally down it is your valve block. If one side goes down more than the other, look for leak on that side. Some shock leaks are internal and you will not be able to pinpoint it. It is possible for the Arnott to be doa. If this is the case Arnott will replace it no questions asked.
My take is that if the truck levels without the compressor running you have one bad shock as the compressor reservoir is very small and has no air to inflate both shocks at the same time.
Let us know.
Last edited by alx; 08-21-2015 at 10:36 PM.
08-22-2015, 03:46 PM
#3
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2007 GL450
Coming in this morning, distance from ground to fender lip:
31 1/2” driver
30" passenger
After door open/close leveling:
34" driver
33" passenger
Looks closer to even deflation than distinctly one side versus the other.
Is the driver side supposed to be 1" higher before I get in?
31 1/2” driver
30" passenger
After door open/close leveling:
34" driver
33" passenger
Looks closer to even deflation than distinctly one side versus the other.
Is the driver side supposed to be 1" higher before I get in?
Last edited by eric_in_sd; 08-22-2015 at 04:46 PM.
09-30-2015, 03:16 PM
#4
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2007 GL450
Arnott sent a replacement strut / spring. I swapped it out and did a pressure test on the old one with soapy water - hooked up about 30 psi from air compressor. Sure enough, multiple slow leaks on the outboard side, all in a row, presumably where the fold is at normal ride height.
I haven't replaced the other side because it's not leaking yet. Kind of disappointing, as the Arnott air spring got about the same life as the OEM, and the vehicle has about as good a life as one could ask for. Moderate humidity, sleeps inside, and frankly spends about 95% of its life indoors.
At least it's got a lifetime warranty, with no shipping charges. So kudos to Arnott for at least standing behind their product, which is more than I can say for MB.
I haven't replaced the other side because it's not leaking yet. Kind of disappointing, as the Arnott air spring got about the same life as the OEM, and the vehicle has about as good a life as one could ask for. Moderate humidity, sleeps inside, and frankly spends about 95% of its life indoors.
At least it's got a lifetime warranty, with no shipping charges. So kudos to Arnott for at least standing behind their product, which is more than I can say for MB.
