E70 Rear Air Strut / Airbag Replacement DIY
 

Repair was done on a 2007 E70 3.0 with Sport Package, 3rd Row Seating and roughly 107,000 miles.

So I had been noticing over the past 6 months, off and on, that the left rear of the truck would sometimes begin to sag overnight...at totally random intervals and seemingly unrelated to minor ambient temperature flucuations. In the morning it would always pump right up if it was required and the compressor did not seem to run more than usual. I finally took the time to pull the left rear wheel off and soak down the airbag with soapy water and was able to determine that there was a pinhole (if not smaller) sized leak near the bottom of the strut where the metal band goes around it...you had to look very closely to even see it and it was easy to miss.

In any case, I ordered the replacement part from John at the Davis Automotive Group (Cleveland BMW) where I get all of my parts from and the following are the steps I took to rectify the problem. A big thanks to "HaroldC" for the pic of the jacking points and "Jarola" for the write-up.

NOTE: I assume no responsibility for injuries, death or improper installation as a result of this write up.

Tools required:
17mm Socket and Ratchet to remove the wheel
Large jackstands (I used 6 ton ones)
Large Floorjack
10mm open-ended wrench
Small prybar

http://i237.photobucket.com/albums/f...s/DSC08796.jpg

Part ordered:
37-12-6-790-078 - $200 + shipping (this part alone costs over $400 at a Canadian dealer)

http://i237.photobucket.com/albums/f...s/DSC08782.jpg

This is how much the X5 was sagging in the mornings
http://i237.photobucket.com/albums/f...s/DSC08776.jpg
http://i237.photobucket.com/albums/f...s/DSC08778.jpg

Here is Jarola's write up and the differences to how I did mine:

1. Used BMW software to deflate the airbags. Removed the fuse under the glove box to prevent the air pump from turning on. I skipped this step and just waited until the next morning when the airbag was fully deflated. I also didn't bother removing the fuse as I had no plans on opening any doors which would energize the system.

2. Jacked up the rear end via jack on the rear diff (I always use a hockey puck in the cup of the jack to avoid damaging anything) and used 6 ton jack stands.
http://i237.photobucket.com/albums/f...s/e70_jack.jpg
http://i237.photobucket.com/albums/f...s/DSC08781.jpg

3. Removed wheels.

4. Removed nut from rear shocks to lower the suspension to give room for the removal and replacement of the springs. I skipped this step as there seemed to be a lot of room available.

5. Popped up the bottom of the air spring with a pry bar, it is plastic and very easy to pop up. Twisted the top of the air spring to unlock it from the body.
http://i237.photobucket.com/albums/f...s/DSC08779.jpg

6. Removed the air supply line by removing the 10mm nut. Replaced the nut and hose on the new spring (this is delivered with it already inserted into the top of the replacement spring/airbag so you'll have to carefully remove it and put the brass ring on the air line, DO NOT LOSE THIS - the old ring will break off when you remove it). Made sure not to pinch the air supply line.
http://i237.photobucket.com/albums/f...s/DSC08783.jpg

7. Replaced the air spring by locking it into place in the upper body location, again making sure not to pinch the air line. What I did different here was to slightly compress the airbag and then tighten the nut so that it would stay that way before reinserting it (twisted counter-clockwise IIRC). It may also stay slightly compressed on it's own.

8. Lifted the suspension to pop in the bottom of the air spring, popped in very easily. Since I had never removed the shock bolt I simply kept the airbag hanging and had someone turn on the car so while that airbag inflated I guided it into the lower mount. I waited a few minutes then remounted the wheel and lowered the X5 in increments which allowed the airbag to slowly fill with air...you should hear the compressor working as this happens.

9. Replaced shock bolt. I obviously skipped this step as it was not required in my case.

10. Replaced wheel.

11. Repeat on other side. I only did the one side.

12. Lower truck and replace the fuse. The pump will turn on and pump up the springs. In my case I started up the X5 prior to lowering it all the way but I suspect that since it was still in "lift mode" (see below for more information about the BMW air suspension and the various modes) it only pushed in a minute amount of air. After gently lowering it all the way in increments it should be fully filled and the vehicle level. NEVER allow the full weight of the X5 to sit on an empty airbag!!!

All in all on a scale of 1-10, with an oil change being a 2, this is about a 2. Very easy and quick and should take no more than roughly an hour to do for one wheel from the time you lay out your tools to the time you've put everything away.

BMW Self-Leveling Suspension Information (5-Series and X5):
BMW Self-leveling suspension

As a 3rd seat/self-leveling suspension X5 owner, I say thank you for this excellent post.

Great to know. Since it's so easy to replace on the road, I may just carry a spare when on long trips towing.
Thanks!

Thanks guys. It's time to give back a little where I can to such a great community that has helped me out too many times to mention. :thumbup:

Wow, great write up. Did I miss, or did you not say, what the approximate USD cost was? I remember reading something like $1100 per wheel?

Well done, thanks

I paid $200 for the airbag + $30 or so for shipping to Canada. The stealer here likely would have charged roughly $600-700/wheel...that would be my best guess anyway. I prefer to not let them touch my vehicle whenever possible...

Great info! Thanks! Happy holidays!

I am still under warranty but I cringe going to the dealer, although Calgary BMW was good my one trip to them. currently my truck is at BMW Gallery it broke down north of Calgary so BMW road side assistance wouldn't take it to Calgary BMW :rolleyes: one Warranty is up I will DIY my repairs as well. Nice write up :thumbup:

Thanks and hopefully your E70 is back in the road ASAP. If you ever have repairs needed after your warranty runs out that you don't want to or can't deal with, I recommend using: Vitek's AutoWorks - HOME

I have them do my transmission fluid flushes as I can't be bothered to get under the vehicle to do the change all the while monitoring temperatures and rowing through gears...Vitek, the owner (absolute stand-up guy and the one person that gets to touch my BMW's in town) tells me we have the cleanest tranny fluid in Calgary. :D

Can anyone confirm this is the fight part number?
37126790078
Thanks

Great write up, will be tackling this soon.

Do you have Adaptive Drive? There are 3 different part numbers. That's the correct part for a car equipped with AD.
http://www.realoem.com/bmw/showparts...79&hg=33&fg=50

Great question, I don't know.
Any idea how I can check? Also, is this the Sam part for both sides?
Thanks

Yes, I do have adaptive drive, checked my vin against Ð*аÑ�шифровка VIN BMW :: BMW :: Первый Интернет журнал об автомобилÑ�Ñ… BMW :: Ð’Ñ�Ñ‘ о BMW, новоÑ�ти, Ñ�татьи, обзоры, фото БМВ
Cool.
Thanks. Is it same fr Bo sides though?

It looks that way to me. If they were different they would be called out individually in the diagram and there would be line items for each part number called out with "Left" or "Right". I think you're good.

Just did this before going to the office this morning. Hardest part was getting the silly rubber hat on the top. Easy job.

can you guys confirm the airbag exists only if you have 3rd row?

Earlier cars could have load-leveling without 3rd row. It could be ordered separately, or the addition of the spare tire triggered the option for it. Later models only got it with the addition of 3rd row seats. I think the cut-off year was 2010-2011, but I'm not sure.

Great write up.

Ive found that my drivers side does this as well. Although my problem seems to be sort of random. For months Ive had no issue and then lately more often than not after sitting for a while that side will be sagging very low. Ive ordered another bag to replace as I hope this does the trick. Any other thoughts on what it could be but the bag/spring?

I ended up changing my bag and it was definitely the problem. When they start to fail they must have very slow leaks. Coincidentally the dealer even had a bag in the box ready to go back for warrantee.

My only feedback for this DIY is that after you install the bag.... turning on the rig while raised up may or may not automaticly inflate the bag. I too slowly lowered the car but it was not filling properly. At that point I was afraid that I did not connect the bag correctly. So I went a head and shut off the car. This helped because I could actually hear the compressor. I then locked the vehicle. While locked I slowly started to lower and by default the compressor started to pump up the bag. After 30 second or so its was high enough to let down the vehicle and after the first short drive the vehicle returned to normal height in the rear. All in all it took me maybe 45 min to change this part. :cool:

I tried to attack the problems this morning. The problem I had was when I raised the car, the bag inflate and extended even the key was not any where the car. In the picture, it seem the bag is in original state: soft and not extended. Mine was fully inflated and raised as the car went up. I could not take it off. does that happen to you guys too: the bag inflated and extended when you lift the car.

I know there is a post suggested to cut the bag open to release the air. Wanted to try it but want to see if anyone has the same problem and what is the trick to remove it. Thanks

ALX5

How about disconnecting the battery so the compressor cannot inflate the bag...

Either disconnect the battery or pull the fuse for the compressor. :cool:

I just finished doing this with the Arnott bag for my right rear. Pretty simple and straightforward. The only gripe I had was lining up the tabs at the top of the bag for the mounting location.

Just a note to those with Adaptive Drive: I took off the negative of the battery as I didn't know where the fuse box was. After reconnecting and getting everything sorted, the 4x4 and Adaptive Drive OFF errors came on. I suspect it'll go away after a few power cycles as it usually does when I get those errors due to work.

It will go away once you drive off

And so it did. :)

Just finished installing Arnott bags as well. The problem I'm having now is the instructions say to insert the line into the hole and tug on it gently to ensure it is properly seated. When I tug on it it just want's to come right back out. It seems the brass retainer ring isn't grabbing onto and holding the line. Am I missing something? Thanks in advance.

It may be possible that the air line you are sticking does not go into the brass ring installed and you are not pushing it in hard enough.
If the line appears to go all the way in then it may be possible your bag does not have a brass ring installed in it.

That's where I would be looking.

Annnnnnnd, I have to do this myself

I swapped my summers for winters today and noticed the driver's side bag is all chaffed. It hasn't started leaking, but why wait

http://www.wardphotography.com/temp/IMG_4269.jpg

Thanks. I suspect you are right. It probably doesn't have the brass rings. I continued installing it and have been driving around all day. All seems okay.

FYI for anyone buying the Arnott air bags. Just noticed Amazon.com has it on their site for $160/side + Free shipping. Wish I had checked there first.

I've done my bags 4x now, couple of mistakes I have made.
If you do one, do both. The rubber at the creases deteriorates and they both will fail around the same time.
When removing, lead with the top while removing instead of moving bottom of bag out first. Once the bottom is detached turn bag to unlock top and push the bottom towards the rear differential. This will expose the top and allow you to unscrew air line and then easily remove the bag.
Do not retighten the air lines at the pump after you deflate. You will need to expand the new bags once in place and if you have tighten the air lines this will nearly be impossible.
Make sure you click the lower in place.
Validate proper inflation once inflated.

As an fyi, stan's no tubes sealant will seal any leaks. Had to use it in a bind while waiting for shipping and actually the bag held for 3 months.
Careful with the brass compression fitting, they will split in half if reckless.

I just changed my rear driver side airbag but now I'm having second thought of not replacing the other side. When I park my X on somewhat of an incline at work, the rear passenger side is sagging close to the tire but does go up while driving. Dealer charged about $400 for the one side.

Should I just fix the other side even though it's not poped?

Yes, get it replaced right away...but why get replacements from the dealer? Arnotts would supply both left and right rears for just under $400 if I'm not mistaken. And since fitment is really no more complicated than following a very simple "how to" instructional video on their website there's no reason not to DIY.

If you don't have the proper tools including jacks and stands it's not worth the effort. $400 is pretty respectable considering.nwonder why they didn't try to both.

Considering they are $160 per side on Amazon, and this is about a 2 on the 1 - 10 difficulty scale for DIY, I'd opt to save some money and DIY. I don't like paying for stuff I can do myself.

Arnott air spring users, do you have to remove the brass nut that came already installed in the new bag off and reused the brass nut on the air supply line?? Or do I just insert the air supple hose only to the new arnott bag??
Thanks, Sam

Sam, best advice I could offer is to have a look at the video instruction on the Arnott website. I used everything supplied in the kit so if they had supplied new ferrules and nuts then I would certainly have removed the old ones.

On the arnott installation video, it says to toss out the old air supply line brass fitting on the old bmw bags and just insert the air hose. Is this right?? Also the instruction say to insert the air hose and gently pull it. When I do that the air hose pull right out, there nothing stopping it from pulling out. Is this normal?? Thanks, Sam

This is NOT correct Sam. It's been a while since a replaced mine but I'm certain the airbags where supplied with new brass ferrules. The reason you are instructed to gently tug on the lines is to make sure you've correctly fastened them to the bags...which will be impossible to do without the ferrules (brass retaining rings) so if you didn't get any in your kit then I hope you have not thrown your old ones out because you will have to reuse them.

The bags came with the brass nut already installed. But I didn't see the little brass locking nut inside. While watching the installation video, I didn't see them taking out the brass nut when they were installing the air hose. Does this mean I have redo it?? Thanks, Sam

If it's not leaking then I suppose you could adopt the principal of "if it ain't broke, don't fix it". But if we're both referring to tiny brass rings that should be slipped around the pipe ahead of the nuts and you have by some chance removed them then the likelihood is the pipes will be easily dislodged by air pressure or by other mechanical means and you'll be left without suspension. Like I said before, it's been a while since I replaced mine and the old memory is a little foggy and I would hate to be leading you astray...especially given the potential for misinformation owing to the fact we're trying to explain something to each other without the benefit of visual aids.

Thanks for responding, I'm going to redo it n see if the tiny ring is inside the arnott air bag.

Need to remove any trim inside?
 

Hi,

My Rear ABs aren't leaking, yet (82k) but figure I should do this as preventative maintenance like the trans fluid flush. From reading this thread it sounds like there is no trim removal needed in the interior, is that correct?

Thanks,
John

Yes that's correct, you can see the tops of the bags in the upper right and left hand corners once you lift up the trunk floor where the spare tire/battery is.

Completed this today, thanks for the great DIY thread!

Thanks,
John

Have to complete this job this weekend. Looks very easy but still reading for any additional notes.

:thumbup:

Anyone have a source for the least expensive OEM air pump? I recently replaced both bags as my truck was leaning to one side each morning. Now, the truck is evenly down in the rear each morning and pump is horribly loud. Time for a new pump.

Try BMW of South Atlanta Online Store.
BMW part cheaper and shipped.

Thanks to everyone, and specifically the OP, for providing such excellent info. I did both in under an hour. The new bags from Arnott have pre-installed fittings, so all you have to do is slide the line into the fitting, pull gently to make sure their set, and thaz-it!

Very easy job for even the most junior mechanic. You can do it!