Air Suspension Leak Down after Sitting 2 Weeks

[WalleyeMikeIII]

Hey all, not sure if this has happened to anyone, but thought I would ask. Returned from a 2 week vacation and noted the rear air suspension in my YukonXL had leaked down and my rig was squatting in what seemed to be the lowest setting, although the front had a bit more height.

Started her up and it aired right back up again, and is holding; no error messages or waring lights on the dash after startup.

So, is this "normal" or signs of bad things on the horizon. It definitely does not leak down overnight, or anywhere close to that...

Called the dealer this morning and they said if it aired back up and no lights on, and is holding air...not to worry....

 

[Joseph Garcia]

Get yourself a squirt bottle with some soapy water and bubble test the shock bladders, air lines, and air line connectors to see if you have a slow leak. Small leaks eventually turn into fast leaks.

 

[WalleyeMikeIII]

Get yourself a squirt bottle with some soapy water and bubble test the shock bladders, air lines, and air line connectors to see if you have a slow leak. Small leaks eventually turn into fast leaks.

This is actually a really great idea...

 

[Big Mama]

Joe is right and it shouldn’t leak down at all. Don’t let the dealer get away with that. I don’t think there’s a light from the system leaking air.

 

[WalleyeMikeIII]

An Update, this weekend wife and I were out of town in her vehicle, so mine sat from Thursday about 5pm. Sunday around 6pm when I arrived back at my house, I noted again that the rear was lower than the front. This time I took out the tape measure and the camera. Sure enough, the rear was 2" lower than the front (distance from ground to highest point in wheel well). I keyed on the vehicle, but did not start the engine, by holding the start/stop button for 5 seconds. I shut the doors and waited. Heard a few clicks, and then the rear end rose up, to same height as front. Front did not move. Compressor did not kick on, presumably it just used reserve air from the tanks. Have an appointment for Monday at the dealer, provided them w/ pics and the description. This morning I measured it down about 3/4" from its full inflated height.

Seems like one of the rear shocks, hoses, fittings is leaking...will see what dealer finds.

 

[Doubeleive]

An Update, this weekend wife and I were out of town in her vehicle, so mine sat from Thursday about 5pm. Sunday around 6pm when I arrived back at my house, I noted again that the rear was lower than the front. This time I took out the tape measure and the camera. Sure enough, the rear was 2" lower than the front (distance from ground to highest point in wheel well). I keyed on the vehicle, but did not start the engine, by holding the start/stop button for 5 seconds. I shut the doors and waited. Heard a few clicks, and then the rear end rose up, to same height as front. Front did not move. Compressor did not kick on, presumably it just used reserve air from the tanks. Have an appointment for Monday at the dealer, provided them w/ pics and the description. This morning I measured it down about 3/4" from its full inflated height.

Seems like one of the rear shocks, hoses, fittings is leaking...will see what dealer finds.

what tanks? the T2's have air tanks?

 

[WalleyeMikeIII]

what tanks? the T2's have air tanks?

Yes, there are air storage tanks for the 4 corner leveling system.

 

[Big Mama]

Air tanks? How cool is that? Still makes no sense that the rear goes flat.

 

[Doubeleive]

Yes, there are air storage tanks for the 4 corner leveling system.

View attachment 441542

ok, well 2-weeks is a slow leak you will need to spray with soap and water mix and examine closely for any bubbles, that slow of a leak will likely be hard to find mostly because you can't just dip it in water like a tire. you going to have to lay under there and look, might help to back it up on some ramps for more room
you will want to concentrate on the shock bladders, air pump & relief valve, and around those tanks inlet/outlet
if the tank is plastic maybe spray all over, if they are metal then less likely to be a crack in the tank

 

[WalleyeMikeIII]

ok, well 2-weeks is a slow leak you will need to spray with soap and water mix and examine closely for any bubbles, that slow of a leak will likely be hard to find mostly because you can't just dip it in water like a tire. you going to have to lay under there and look, might help to back it up on some ramps for more room
you will want to concentrate on the shock bladders, air pump & relief valve, and around those tanks inlet/outlet
if the tank is plastic maybe spray all over, if they are metal then less likely to be a crack in the tank

Tanks are aluminum. It’s warranty, so taking it to dealer. Hope the tech is motivated…

 

[Doubeleive]

Tanks are aluminum. It’s warranty, so taking it to dealer. Hope the tech is motivated…

lol, ya good luck. "maybe" they have a method to externally pump it up to higher pressure to help detect a leak.
I would expect to be put at the end of the line on this one....especially being warranty

 

[WalleyeMikeIII]

lol, ya good luck. "maybe" they have a method to externally pump it up to higher pressure to help detect a leak.
I would expect to be put at the end of the line on this one....especially being warranty

It did leak down afte 3 days this weekend, so I may ask them to just keep it a few days and watch it. They are providing a loaner, so we will see. I documented the issue w/ photos as well...dealers around here are pretty decent, will see.

 

[Doubeleive]

It did leak down afte 3 days this weekend, so I may ask them to just keep it a few days and watch it. They are providing a loaner, so we will see. I documented the issue w/ photos as well...dealers around here are pretty decent, will see.

that should make is easier to find, they could come back with "that's normal" or some crap, even though we all know it's not. good luck

 

[Big Mama]

You might also look to see if GM put out any TSB’s on this issue.

 

[WalleyeMikeIII]

You might also look to see if GM put out any TSB’s on this issue.

Pretty up to speed on most of the TSB's, there was one early in production for very cold climates...but my vehicle was built after the engineering change to resolve it. And, it is not a cold weather thing...has been plenty warm here...at least until today.

 

[Fast_AT4]

 

[Polo08816]

Not a good sign for a 2 year old vehicle. This makes me very wary of the air suspension (on any non-commercial application). We went to test drive a few 2024 Suburban gas variants (5.3L and 6.2L). I noticed the 2024 Suburban Z71 with Air Ride suspension's rear was lower than the front by about 2" when it was parked before the test drive. It did return to normal height at some point during the test drive.

 

[WalleyeMikeIII]

Not a good sign for a 2 year old vehicle. This makes me very wary of the air suspension (on any non-commercial application). We went to test drive a few 2024 Suburban gas variants (5.3L and 6.2L). I noticed the 2024 Suburban Z71 with Air Ride suspension's rear was lower than the front by about 2" when it was parked before the test drive. It did return to normal height at some point during the test drive.

I bought the air due to my frequent towing…and for that it’s great.

 

[WalleyeMikeIII]

Well, the dealer had it today for diagnosis. Was returned as “operating at designed.”

The dealer returned a document from GM explaining the Air Suspension Operation. A pic of that document is attached. It says sag is normal to the tune of 2mm (0.08”) in 24 hours at constant temperature. So, my 1-1.5” in 72 hours exceeds that.

I’ve e-mailed my service advisor for further clarification and suggested we let it sit in their climate controlled facility for 72 hours and measure it every 24, to see if it is still in spec. Haven’t heard back.

 

[Doubeleive]

Well, the dealer had it today for diagnosis. Was returned as “operating at designed.”

The dealer returned a document from GM explaining the Air Suspension Operation. A pic of that document is attached. It says sag is normal to the tune of 2mm (0.08”) in 24 hours at constant temperature. So, my 1-1.5” in 72 hours exceeds that.

I’ve e-mailed my service advisor for further clarification and suggested we let it sit in their climate controlled facility for 72 hours and measure it every 24, to see if it is still in spec. Haven’t heard back.

FIGURED AS MUCH
my advice is go out and stick a sewing needle thru that bladder a few times, then take it back and say "check it again"
but do it on the bottom edge where it rolls so it doesn't look suspicious