DIY F11 Air Spring replacement

[Cadwell Parker]

Some time ago my car needed a new air spring. In the absence of any other info on the subject being easily found online I made a lengthy post on the old forum detailing the procedure. Sadly the online version seems to have been lost with the old forums demise. I didn't keep a copy but still have the photos I took at the time and while it's nearly three years ago and my memory is hazy I'll do my best here to set out an overview of the procedure.

The job can be done with only a few basic tools. You'll need a suitable jack, axle stands, an open ended spanner (10mm from memory but don't quote me on that), a large flat bladed screwdriver and a laptop with software for deflating the old springs. You can get away without the laptop if you need to. You can deflate the springs by disconnecting the compressor end of the air lines but there's more dismantling to be done this way. I had the software and used that because it was easier and I didn't want to disturb any more parts on the car than necessary.

Jack up the rear end of the car and support safely.

It's ok to jack the car on the brace plate but bear in mind the car will have a tendency to roll forwards so you'll need to chock the front wheels.

It's also OK to jack the car on the diff housing but be very careful to avoid catching the rear cover with your jack or mess and damage will ensue.

Remove the wheels and deflate the springs using whichever method you choose. You should find the rubber soft enough to push in easily with a finger.

Looking at the underside of the bottom spring mount you'll see three plastic tabs protruding through the hole in the middle.

You need to disengage these tabs to free the bottom of the spring from the mounting point. I used my long levering screwdriver to push one tab in while simultaneously twisting the spring slightly with my other hand to keep the tab from springing back while I pushed in a second tab. Once you have two tabs disengaged there's nothing to hold the third in place and you should be able to twist the spring in the right way and pull the bottom of the spring clear of the mounting plate.

Now to disengage the top mount. When the spring is deflated and disengaged at the bottom you'll find its quite a loose fit at the top. I recall having trouble getting it in just the right position for it to drop out. After struggling for a while I paused to work out where I was going wrong. When I went to try again it more or less fell out as soon as I touched it. Once you get it turned to the right position it should drop out easily. IIRC you turn it in an anticlockwise direction if you were looking down at the top of the spring from above. If you have a new spring ready to fit you should be able to look at the shape of the moulding on top and work out which way to turn the old one.

Now the spring is free at both ends you can use the open ended spanner to remove the air line connector from the spring body. They aren't very tight and should be easy to unscrew.

Be careful not to bend or pull too much on the air line. If you bend it too far it can get kinked and restrict the air flow. With the connector removed from the spring you should now be able to pull it from the end of the air line along with the sealing olive. It's good practice to tape up the open end of the pipe when it's disconnected and so avoid any foreign bodies finding their way into the system.

The air spring is now completely disconnected from the car and ready to remove. I recall it being a bit of a tight squeeze but there's enough space to move it into a position where you can pull it through the available gap and away from the car.

The bellows didn't look too bad while fitted but off the car it's easier to see why they don't always loose pressure in a predictable way. The rubber is perished where it folds over itself. Eventually pin holes develop in the area of the fold and can leak depending on how the car is sitting, how the rubber is folded over itself.

My new spring was an Aerosus item. I don't know whether air springs usually come with a new dust cover supplied or not. Mine didn't so I had to refit the old one. Fortunately it was a good fit on the new spring, I just had to slightly modify the hole through which the air line passes.

BMW say the ends of the air lines should be absolutely pristine and undamaged if refitting them otherwise a good seal is not guaranteed. My line was not in a pristine condition. The outer surface appeared to have been scored by the connector. If necessary you can cut back the end of the pipe to give you a clean end. If doing this you need to be sure to cut the pipe cleanly and at a 90 degree angle to ensure a good seal. I thought about doing that but I was going to have to cut off an inch or so and there didn't seem to be much spare length on the pipe. With the car being in daily use and wanting to avoid cutting the pipe too short leaving the car off the road for any length of time I chose to take a chance and just reconnect the air line as it was. Turned out it sealed just fine the way it was and at the time of writing this has been good for 70000 miles. The new spring came with the  connector already in place. No spannering was needed, just remove the while plastic sealing plug, remove the tape from the end of the air line and push it into the connector as far as it'll go before pulling it back out slightly till it stops. This last part is important as it's what creates the seal.

Now you can install the spring in the top mount,  being very careful not to trap the air line between the top of the spring and the body of the car. If you do you'll need to dismantle the whole lot again and probably have to replace the squashed air line.

Locate the top of the spring in the top mount and turn until it stops to lock into position. At this point the spring still felt quite loose to me but it seemed to be locked in position. After a few attempts at refitting it didn't feel any tighter and remembering how loose the old one was before removing it I was confident I had it in the right place.

To begin with I struggled to get the tabs to clip on to the bottom mount. It was difficult to apply enough downward pressure on the base of the spring. The easy way to do it I discovered is simply to inflate the spring. This way it pushes itself down onto the mount with enough force to engage the tabs.

Now you can refit the wheel, remove stands and jack and go for a drive.

 

 

[Munzy]

Great write up and photos - thanks for posting! 

Defo one for the favourites folder 🙂 

[JCP]

I changed mine based on your excellent writeup on the old forum - so pleased you have taken the time to add it back here. I was thinking the other day it was a shame that guide had been lost!

[Cadwell Parker]

On 14/10/2022 at 15:08, JCP said:

I changed mine based on your excellent writeup on the old forum - so pleased you have taken the time to add it back here. I was thinking the other day it was a shame that guide had been lost!

Thanks, glad to hear it helped you 😀

[VPCAPTAIN]

Thanks for spending time to re-write @Cadwell Parker looks like my 65 plate F11 starting to need a new rubber spring as when parked overnight the osr drops to the stop and although it re pressurises on start up is needing attention.

would you mind advising on your supplier for the airspring as Autodoc only lists  Vemo at £320 

many thanks hoping @Andrewwill be able to help fit 👍

[VPCAPTAIN]

2 minutes ago, VPCAPTAIN said:

Thanks for spending time to re-write @Cadwell Parker looks like my 65 plate F11 starting to need a new rubber spring as when parked overnight the osr drops to the stop and although it re pressurises on start up is needing attention.

would you mind advising on your supplier for the airspring as Autodoc only lists  Vemo at £320 

many thanks hoping @Andrewwill be able to help fit 👍

Not to worry found Aerosus website 

 

 

[Percha]

I used Arnotts and they are very good quality, mine went on at ~60k now at 85k and they felt better than OEM once replaced:https://www.autodoc.co.uk/arnott/13243669?gshp=1&gclid=Cj0KCQiA54KfBhCKARIsAJzSrdrya3SulBE9nv8qMSpDuRsJGbCnlGXPiFjwZLryliQdI08S05GDah4aAnYKEALw_wcB 

Cheaper than Aerosus so maybe worth considering.

Edited February 6, 2023 by Percha

[Rolo]

I had to replace one of my rears about 4 months ago and bought a Dunlop one from eBay. 
It seemed to be decent quality ( Genuine Dunlop ) , fitted no problem and cost me £108, which feels like good value.

No issues so far, car rides good and saved me a good few quid, so I’m more than happy with that 😁
 

Edited February 6, 2023 by Rolo

[VPCAPTAIN]

Thanks @Roloand @Percha

as i dont want the F11 off the road too long I’m going to buy a set of rubber springs from either Autodoc ( found the Arnotts link and their website says they are better than the bmw original ones.  Also saw the dunlop ones too.

A quick question likely to keep my 65 F11 for another 3-5 years and dont want the air springs to fail again - have seen on ebay replacement springs starting at £25 each non oem - would it be false economy to use the cheap chinese ones and have to replace yearly or do you think they would fail a lot more often ?

AUTODOC doing Arnott A-2780 at £157.22 each 

ebay has DUNLOP at £120 each

appreciate any real world experiences on the cheaper ones 

 

but to be honest they dont appear too difficult a swap out once car safely on axle stands with wheel off and the suspension de-pressurised

Thanks

[Andrew]

13 hours ago, VPCAPTAIN said:

 

many thanks hoping @Andrewwill be able to help fit 👍

Lol

i don’t remember volunteering for that job!😂

Can’t say I’ve got much air spring experience 

[VPCAPTAIN]

Ahh well @Andrew your next 5 might  have air suspension so the experience will come in handy 🤣

[0011718]

Hi VPCAPTAIN, I purchased these last year as a spare set in case mine started to go but haven't used them uet. Had my 2014 F11 15 months now and it's on 115k and I don't know whether they have been changed at all since new? I figured for the price even if they last only a couple of years they would still work out cheaper changing them every 2 years than buying OEM. They're currently offering an extra 5% discount making it £54 for the pair!

https://www.amazon.co.uk/Suspension-Spring-Bellow-Strut-37106781827/product-reviews/B01FWZ6BFU/ref=cm_cr_arp_d_paging_btm_next_2?ie=UTF8&reviewerType=all_reviews&pageNumber=2

Edited February 7, 2023 by 0011718

[VPCAPTAIN]

Thanks @0011718just looking at those - amazing to see they get a fairly good review too - watched a number of youtube install videos and confident enough to install replacement air springs.  (Along with NewTIS and Haynes instructions and @Cadwell Parker excellent post above.)

@Andrew my neighbour and mentor knows that I will almost always go stealer or oem for both of my bmw’s despite their age to keep the german quality - but saying that it sounds like on this occasion the installed air springs are made in china - with the current state of the roads in Scotland even genuine oem might not last any longer than pattern parts.  
 

Hoping to strip the car later today to confirm its an air spring leak and not one of the output solenoid valves leaking and then will decide which supplier to buy and post an update.
 

As Dunlop make good tyres think I’m going along the route they make good air springs so they are excellent value with a 2year warranty. (Found for £109 each) 

thanks 

 

Edited February 7, 2023 by VPCAPTAIN
Extra info

[Rolo]

My logic was that OE ones were too expensive and others too cheap so I went somewhere in between and also assumed that the Dunlop rubber would be decent quality, right or wrong , we’ll see ! If you can get a pair for that price then all the better.

As for fitting them, anyone who can use a spanner without needing a manual should find it straightforward. 
Watch the YouTube videos, jack the car up safely, take your time, don’t over tighten the pipe unions and it should take you about 20 minutes or so. I don’t have software to deflate etc. so just drilled a 5mm hole in the bag to start and the car inflated by itself when done. Probably saved a lot of time anyway.
One tip, which I know might be stating the obvious but , DO NOT stretch out your new air spring before fitting it, you will regret it ….. 🙄 ! 

Good luck and happy fitting 

[Munzy]

8 hours ago, Rolo said:

so just drilled a 5mm hole in the bag to start and the car inflated by itself when done.

This!

I've done it twice now. First time I spent an age doing it the proper way - taking the cover off under the rear of the car to access the compressor which was reasonably fiddly and totally unnecessary in hindsight. 

Second time I used my NT530 to drain the bellows but after two cycles there was still air in them. So I resorted to cutting a large slit with a Stanley knife - worked a treat! Two benefits of this method:

1 - saves a ton of time/fannying about

2 - old bag is completely deflated making it even easier to wangle out

I think the only reason more people don't do the stabby method is safety but unless you have your face 2 cm away from the bag and are sensible I can't see any reason not to.

As for the quality vs price debate, I've used the cheap (£60 pair) both times.  The right hand side lasted about a year then I replaced both in July 2021 and there are still in there (I hope I have not jinxed it!).

Much the same as above I usually like to go OEM/BMW parts but I'd be gutted if I spent £350+ for them to potentially fail anyway and from my point of view a rubber air bag is such a simple part that the performance won't be like the difference between quality and cheap traditional metal springs.

[Cadwell Parker]

On 06/02/2023 at 22:02, VPCAPTAIN said:

appreciate any real world experiences on the cheaper ones 

IIRC someone on the old forum had used cheap bags from Ebay for £30 each which they claimed lasted upwards of 80000 miles. They also had to replace one which leaked as soon as it went onto the car.

I fitted Arnotts and they've been on the car for 80000 miles with no issues at all although obviously not the most affordable option they uave easily outlasted the OEM items.

On balance I'd say the Dunlops seem a good compromise.

As said above it's an easy job. Once you know how you could do both sides, get cleaned up and the kettle on easily in under an hour.

[VPCAPTAIN]

Thanks @Cadwell Parker agree that your Arnott / Aerosus ones sound the best available and the very cheap ones would be pot luck.

@Andrewand me also think the Dunlop would be a good compromise from a reputable manufacturer.

Bought two due today - weather permitting will fit the two and try and get some good shots to complement your write up.

cheers Rob

Edited February 8, 2023 by VPCAPTAIN
Spelling

[VPCAPTAIN]

Hi @Munzyreally appreciate your comments and have a foxwell I was going to attempt to bleed the springs as per NewTIS / agree removing the compressor covers to unscrew the connection from each outlet seems an unnecessary step - and although a risk exists in cutting the existing airbag - if your careful It should be reasonably safe if the car is well supported and your not below the hub.

I plumbed for Dunlop as work away and didn't want to risk a premature failure on a long drive away from home.

thanks again to all contributors

[Andrew]

On 06/02/2023 at 22:41, VPCAPTAIN said:

Ahh well @Andrew your next 5 might  have air suspension so the experience will come in handy 🤣

Um, how can I say this,

 

NO!

 

😆

[VPCAPTAIN]

Hi well attempted the osr spring and it was a little trickier than I had imagined but i got the old spring out - fitted the new one - and repressurised both looked good - took it for a drive again looked good sat 5 mins and the new osr spring had gone flat - 🙈.  Im hoping its just the air line connection isnt 100% sealing but wont be able to have a look until next wed / thu due work.

took loads of photos but again will hold off posting until i have it fixed

 

 

[Greenfingers]

On 07/02/2023 at 11:28, Rolo said:

DO NOT stretch out your new air spring before fitting it, you will regret it ….. 🙄 !

Found this out the first time I changed one - thought it would be a good idea to inflate the bag a bit to help it seat at the bottom by switching on the ignition, but the compressor kicked in as soon as I opened the driver's door and the whole thing popped open! After a lot of swearing and with great difficulty I eventually managed to fold it back inside itself.

Changed my 3rd bag in 50k miles today; a £27 eBay one again, which I think makes sense economically, particularly if you deflate the quick way with a knife.

[VPCAPTAIN]

I must admit it didnt inflate straight first time i repressurised - it somehow although lined up with bottom hole ended up 90degs bent.  On deflating then holding it over the hole it inflated correctly second time and engaged in the bottom hole - just hoping it didnt get damaged internally. I had followed the original post instructions and pulled fuse between fitting 

Edited February 9, 2023 by VPCAPTAIN

[Greenfingers]

Cadwell Parker's write up is very helpful and correct, but having done this job 3 times, I have found some things that can be simplified:-

1) If you don't have an electronic tool to deflate the bag, just stab it with a knife. This saves all the hassle of disconnecting the line at the valve block and also potentially creating another leak there (the plastic thread that the brass ferrule screws into is very soft plastic and easily damaged).

2) When fitting the bag at the top, there's no need to remove the brass fitting if the O ring is in good nick - you can fit the rubber shroud by cutting a slit in it just above the hole instead of feeding the line through.

3) It's easier and safer to engage the bottom of the spring in it's location using a scissor jack or similar to raise the suspension arms, rather than pulling down or inflating. Once it cllicks into position it won't come out.

[VPCAPTAIN]

Thanks @Greenfingers

much appreciated and I couldnt believe it when i inflated ( scan tool ) - heard the expected pop noise ( expecting it to be engaged in the bottom hole but to my horror seeing it bending away 🙈 (pics 1&2)

after deflating it did sit in the hole and inflated normally but it sounds like an internal seal got damaged (pic 3)

[Andrew]

I don’t think all is lost @VPCAPTAIN, we might be able to wrestle the air bag back together on the bench as per @Rolo and @Greenfingers advice