Air Suspension - Deflating

[lht5059]

Originally Posted by AustraliaG20

My F15 is having both sides of the rear drop after sitting for a couple of hours, it has only started today but (so far) is very consistent. Once the car is started it will pump back up. BMW are not cheap! $1020 per bag, plus labour... plus time is insane. I am very tempted to just do it myself, but I have sold all my tools which is very annoying. Anyway, a few questions if people can help to just narrow down the problem.

- If both sides go down evenly, can it still be a leak? Initially I would have thought each bag would be separate from the other, but that might not be true. With one compressor, will a leak in one side produce an even drop across both - ie. is it a single system? I am just trying to confirm it is likely the air bags as both getting a leak at the same time seems unlikely. I don't have tools to easily lift it and check for leaks, but I might have to borrow some tools.
- Since the compressor inflates the air bags, I imagine it is fine?
- Where exactly is the compressor? I would like to check that it isn't running 100% so I can drive it around while I wait for a fix / parts. I assume just listening is enough, but there is a shield under most of the car. I am hoping that I can slide under the car and hear it.
- Do I have to buy ISTA and an E-Net cable to reset it all?

I think that's it. Thanks all!

1. Yes and no. This could mean both sides are leaking, or could just mean your airline and/or compressor is giving out.
2. A leak in one side will not affect the other. One of mine was basically gone while the other sit fine. The good side will sag down a bit because... well physics, but would not go down the same.
3. The chances of you finding a hole of sort for this kind of leak is rather small. It's more like the bags are stretched out at the portion where they roll inward in the bottom. Maybe use some soapy water in a spray bottle and spray around the bags to see if there are any obvious leaks, like how you would identify a nail in your tire--this might or might not help.
4. If either your compressor, line, or bags are leaking, I would not leave anything alone. Assuming that your bags OR lines are the trouble maker and everything else is fine, your compressor will be compensating for the leaks and work overtime. This runs the risk of it going out and that bill is a lot more than just the bags. Also, the price you mentioned above per bag is crazily high... I went with Bilstein instead of Arnott, which is already more expensive, but even then it's not even close to the price of $1020 you listed. All in, this should be less than a couple of hundreds even if you don't do it yourself (hence, not factoring in the cost of buying jack and jack stands or other tools). Find a local indy and show them the videos I listed at the bottom of this response. You don't need an Euro shop for this; I'd actually prefer shops that do a lot of work with air suspension/coil overs for any makes and models; even JDM shops that know what they are doing are more than capable of doing this for a reasonable rate. Read points 5 and 6 and you will see why.
5. The compressor is on the right side, underneath the car. I'm not sure if you would really hear it or not... Didn't pay attention when I got mine done. See the videos below, they changed the bags by taking the air lines out of the compressor and not going with ISTA -- I did the same.
6. Kinda answered it just now. You can use ISTA and I am sure that's the recommended route, but it's not the only way. You can disconnect the air lines from the compressors, let the air empty out, change the bags, replug the lines, turn the car on with the car SLIGHTLY on the ground so that your compressor can fill in some air, and then fully lower it.

Vids as mentioned -- the first one is from Arnott using the same technique in point 6, so that's a bit more reassuring.

[Chilled]

Each of the airbags has its own air line, and they are nicely colour coded. You could try trace/soap the lines, see how that gets you.

The compressor does have a one way check valve that can fail, and that does lead to loss of pressure.

Do you know if the compressor is constantly running, or do you only hear for about 10sec and then it turns off.


Oh, btw. As a fellow upside downer. Check out FCP Euro. Their parts price is not the cheapest, but inc. shipping its usually less then the others. So per bag you'll be at around 700ish AUD delivered.

[AustraliaG20]

Thanks both! I can't find an easy way to see if the compressor is always running. I'll borrow a jack to lift the car up, and take off the splash guard and see how it goes. Both sides are dropping evenly, there is definitely not one side more than the other. I guess that means I should be looking more towards a leak near the compressor.

FYI - The price I mentioned was AUD... but still very expensive!

[Chilled]

Originally Posted by AustraliaG20

Thanks both! I can't find an easy way to see if the compressor is always running. I'll borrow a jack to lift the car up, and take off the splash guard and see how it goes. Both sides are dropping evenly, there is definitely not one side more than the other. I guess that means I should be looking more towards a leak near the compressor.

FYI - The price I mentioned was AUD... but still very expensive!

Oh yeah, still expensive. But 700AUD delivered is better than 1000 AUD. Plus with FCP Euro, they fully warranty the parts for life.


If the back end is down, and you unlock the car/open the doors. The compressor should automatically turn on to raise and balance the rear. You will definitely hear it.

[AustraliaG20]

Originally Posted by Chilled

Oh yeah, still expensive. But 700AUD delivered is better than 1000 AUD. Plus with FCP Euro, they fully warranty the parts for life.


If the back end is down, and you unlock the car/open the doors. The compressor should automatically turn on to raise and balance the rear. You will definitely hear it.

OK. Good to know. I suspect it'll be down tomorrow morning so I'll check it out.

[AustraliaG20]

For those that bought the valve and replaced it, can you confirm the part number and/or a link to the part you used and worked? There seem to be heaps (and a range in price), so I just want to make sure I'm getting the right one.

[wmr71]

just did these yesterday. Arnott A-2642 was the right part for my 2016 x5 50 msport. one side was always leaking and my friend who is a shop lead said they will almost always go out in pairs. to keep from having to do another one soon I spent another $150 and knocked them both out at the same time. It took 45 minutes while on a lift and it now works as new

here they are on amazon for $150 a side:https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[AustraliaG20]

I did it today, same part Arnott A-2642 as above - 2015 X5 M50d. Was two of us, on the ground / jack / stands and took about 60-70 minutes without rushing. Took longer to get one of the wheels off that was stuck to the hub than anything else.

I modified the approach slightly. Removed the fuse. Jacked the car, car stands and removed wheels. Stabbed the bag to deflate. Remove and replace the bag. Repeat other side. Wheels on. Car down. Fuse in. Turn the car on... car raised up. Done.

I used the jack under the control arm to lift it into place and fit the new bag. I wouldn't do it with one jack and no stands. It would be tough to do that way.

[jfandl]

If you're having a sagging suspension from the airbags or compressor, and intend to replace the airbags, I would suggest the following tips (from experience):

Wire an audible buzzer to the compressor relay (near the fuse box, green square) This will allow you to hear if the compressor is being asked to supply air. It's quite handy in diagnosing issues and a wise thing to keep permanently as these airbags do not last.

I took it a few steps further and added an on/off switch to manually force the compressor to activate (handy when the car goes into Transport mode and deactivates the compressor - use ISTA to disable this). I also hooked up two LED's, one to each side of the valve block. This allows me to diagnose which air bag is experiencing the issue. (Probably a little extreme but I wanted to know what the problem was)

When installing a new airbag (or diagnosing a leaking one), use leak detection methods - aka soapy water. Spray it on the airbags and crimp rings. Look for fine bubbles developing to determine if you have a leak. It works on existing airbags and is ALSO important to use on new ones. I had two leaking bags received from a supplier. I took a video and they promptly replace them. Just because they're new doesn't mean they don't leak.

It only takes about 45 minutes to replace the air bag once you know what you're doing and yes, you can do it without ISTA but I recommend you removed fuse 110 - 40A for the compressor while doing the work - or remove the relay. I typically remove the air line at the valve block to empty the airbag, then squeeze the bag by had so its compressed enough to remove.

[Rocquanstephenson@gmail]

I had a problem one side would sag when vehicke is off then once day then other side bust so i replaced with new one now both sides sag when off what should i check next ?

[lht5059]

Originally Posted by Rocquanstephenson@gmail

I had a problem one side would sag when vehicke is off then once day then other side bust so i replaced with new one now both sides sag when off what should i check next ?

Your air-lines and how they are connecting to the bags, then the air-lines themselves, then you have the compressor. You replaced both sides I assume?

For checking the first part, make sure you've installed the lines to the bags correctly. I believe there is a washer there that you need to insert between the tips of the lines and the bags. Spray some soap around the area and see if there are any bubbles. Work your way back towards the compressors from there. There are indy I have used that can take care of this for you in NJ (assuming North NJ) for pennies on the dollar vs what dealers will quote you for, assuming you no don't want to play with it anymore; suspension work is something I don't think worth cheaping out on if you aren't comfortable with it. Last but not least, there is always a chance your new bags are bad...

[5tony]

When I replaced my bags, I replaced the air line connector hardware and had a leak. Had to carefully cut about a 1/2 inch piece of the end of the air line and then reinsert the hardware. Connected to the airbag and has been fine for a year now. I think the air line gets deformed by the original hardware, which then causes a leak at the connector.

[N1ck]

I have been noticing our 2018 has been sagging on occasion. Only 54,000kms on our X5 (33k miles) Vehicle could sit for 3-5 days and not sag, then overnight it would be down 3" and noticeably deflated.

Great wealth of knowledge in this thread and how to YouTube links. I purchased two bags off rock auto for $224CAD / $180ish USD. Took around 2.5 hours for the swap, spent a good junk of time locating the airlines and pump to relieve the air in the lines and bags for removable.

Overnight it looks as if the drivers rear dropped around 3/4" but it might just be me over thinking it. We'll keep an eye on it over the next several days.

EDIT - overnight one side sagged approx 1". I believe the culprit is I did NOT reuse the small U shaped brass fitting on one side as it broke in two upon removal. Does anyone know where to source a replacement?

[tlow98]

Originally Posted by N1ck

I have been noticing our 2018 has been sagging on occasion. Only 54,000kms on our X5 (33k miles) Vehicle could sit for 3-5 days and not sag, then overnight it would be down 3" and noticeably deflated.

Great wealth of knowledge in this thread and how to YouTube links. I purchased two bags off rock auto for $224CAD / $180ish USD. Took around 2.5 hours for the swap, spent a good junk of time locating the airlines and pump to relieve the air in the lines and bags for removable.

Overnight it looks as if the drivers rear dropped around 3/4" but it might just be me over thinking it. We'll keep an eye on it over the next several days.

EDIT - overnight one side sagged approx 1". I believe the culprit is I did NOT reuse the small U shaped brass fitting on one side as it broke in two upon removal. Does anyone know where to source a replacement?

Those fittings are a huge pain, but I’m guessing realoem.com has the part numbers you need.

If you’re going in there again tho, I would just swap the bags with the Arnott models. They don’t use any fitting at all and are super easy. About $150 each. Super high quality and easy to install.

[Chilled]

AustraliaG20 , Hey Did you manage to fix you problem?

I'm now in the same boat, both sides are going down, and it looks like at the same rate. Can take a day or two until its fully deflated.

Did it end up been just the bags, or did you have to mess with the compressor?

[AustraliaG20]

Originally Posted by Chilled

AustraliaG20 , Hey Did you manage to fix you problem?

I'm now in the same boat, both sides are going down, and it looks like at the same rate. Can take a day or two until its fully deflated.

Did it end up been just the bags, or did you have to mess with the compressor?

It was the bags. I had a mate help and we did it all in just over an hour. Pretty easy with the correct tools. It's been fine ever since. I knew there was a chance it might not fix the problem, but given the bags were original they were due for replacement anyway. So just did it and crossed my fingers.

[Chilled]

Cheers. Order a set of Arnotts, lets see how it goes.

[ithatel]

Hi all:
I have read as many threads on the air suspension issues and I’ve really been impressed with the knowledge and help available.
I have a 2016 xdrive35d that has the comfort air suspension system with about 56,000 miles on it. I bought it used with 45,000 miles on it. It came with a BMW installed tow hitch and I can tell it has been used. It was one reason I bought it.
Here is what happens to mine. The only side that is dropping is drivers left rear. And it only happens when I’ve wacked the suspension and then let it sit. So the first time: I backed into the driveway over the rain gutter and up into the driveway and turned it off and went inside our house. When I came back out left rear was down. Sh*t ! I knew what it was and it reinflated. I took it to the Indy shop I’m using and found a ton of codes as the original battery was down and we replaced it. No codes at all were related to the suspension. From reading this forum I knew a bad battery could cause all kinds of issues that are unrelated and all over the modules. I hoped that this was the problem. Sh*t, no !
It keeps dropping after going over speed bumps in parking lots and pumping back up and is fine for days at a time till I’m in a parking lot again.
However, what I notice is that the rear suspension is very stiff after this happens and is about 1/2” higher that it should be. Once this started, I started measuring from bottom of the tire with a tape up along the center of the wheel to the bottom of the arch at that point.
Normal seems to be a tad over 32” and when stiff it is 1/2” higher. After I put the car up for the night, the suspension returns to 32” and not stiff.
So, my plan is as follows:
1. Replacing the aux battery and the compressor relay. It is 7 years old, but measured just passable. I know this battery is for more power for the power steering, but I have read that it also has a roll in the rear suspension. Maybe this will fix it. If not:
2. I have two Arnott bags and I plan on replacing them next. The leak after a suspension jolt may expose a leaky bag that only happens when stressed
3. The way that the suspension rides high for a while makes me suspect the ride height sensors. If the one on the left rear is out of alignment or flakey it might cause the suspension drop after being exercised over a bump. Although the indy ran thru the ride height test on ista (? I forget this name) and it passed.
4. If none of this works, it seems to leave me with leaking supply line(s), the compressor,
or the solenoid valve or ?
Any thing I’m missing ?
We are retired now and down to one car and this bugs me a bit !
BTW, I don’t hit these speed bumps very fast either, they are not wide, but they are high and move the car up and down quite a bit.
Thanks,
Doug

[ithatel]

It has been 3 weeks since my Indy replaced both airbags and the X5
is holding both sides up and I’ve not had a single incidence of the left side sag.
FYI, I used Arnott bags I got at Amazon.
So, I’m cautiously thinking the issue has been fixed. Time will tell.
If it falls on its butt, I’ll let you know.
Thanks for all the helpful info.
In my searches I am surprised the number of makes and models that use a air self leveling suspension.

[hamh]

So my 2016 F15 Msports all a sudden has the rear dropped all the way with the rear fender kinda covering the rear wheel tire after sitting in the garage for 10 days while I was out of town. And I was stupid for not noticing it until I drove the car and feel super bumpy on the ride. Long story short, I dug up the forum, found multiple threads and youtube videos regarding the air suspension leak, and I assume mine is with the same cause, so I ordered two Arnott air suspension, and swapped my old ones out.

These are what I did in sequence:
- Car is off
- Jacked up the car
- Took rear wheels off
- Took off left rear air suspension as I saw it's completely sagged
- After I took the left rear air suspension off according to all these DIY tutorial , I realized I forgot to take off fuse 110
- Not knowing what's the impact is, I still take the fuse off at that moment
- the rear right air suspension didn't appear to be completely sagged, but since I need to replace in pair, and I'm lazy to unplug the compressor, so I lose the rest of the air in it by cutting the bag a little.
- Have both bags replaced, I put back the fuse
- started the car, saw a warning message saying "chassis function restricted" , and the air suspension didn't come back up immediately
- Drove the car around the block, the air suspension didn't rise up visually as much, turned on sport mode, and things start happening visually and finally the air suspension is up
- So I was happy for a day, next day morning, went to the garage, the air suspension still look good and high, but the moment I drove it out, it becomes bumpy again, when I stop the car around the block, I saw the air suspension was low again, and I immediately try to turn on the sport mode because I knew that will kick up the compressor and fill up the air suspension
- Air suspension looked fine after sport mode turned on, drove 30 miles, parked the car for lunch, and on my way back home the air suspension was fine even in comfort mode.

Now I'm hoping tomorrow morning the air suspension stays good and I don't need to do the sport mode trick, but my guts tell me something is still wrong, can anyone help?

[hamh]

Things are still bad, drove the car out for an oil change with the suspension up without any problem, but after oil change, the air suspension won't come back up and turning on sport mode won't trigger the air to fill up.

Any insight would be appreciated.

[rmacgurn]

Originally Posted by hamh

Things are still bad, drove the car out for an oil change with the suspension up without any problem, but after oil change, the air suspension won't come back up and turning on sport mode won't trigger the air to fill up.

Any insight would be appreciated.

curious if you live in wet area? I have a 2018 X6 Msport Diesel euro version and started a few months back did it 1 or two times then stopped. as the seasons got try was fine now its wet again and it happen yesterday after sitting 2 days both side. most here say bags but car as 43K kilometers like 25K miles. next is the desiccant beads or pump valve so I guess I will check that no fuse issues and pump isn't running always so think relay ok. let me know what you figure. your ahead of me doing something to fix.