Suspension airbags

[asoni]

Woke up to find one rear corner completely dropped. Very common and I was expecting it as Bmw told me recently the airbags are worn.

Ordered 2x airbags from eBay £280 genuine Arnott.

I read that if you’re not reusing the airbags you can just stick a hole in them to deflate and remove. No need to access compressor and remove airlines etc.

Is this correct? I’m aware battery needs disconnecting first.

Also, should the car raise to the correct level automatically or will I need to use inpa to level both sides manually?

Lastly any worthwhile jobs to do whilst I’m in that area? Bushes etc.

[Alan Gunn]

Not true i think.
They have a pipe on the top to disconnect to start off with.

[mr angry]

Cant see why you couldn't do this but accessing the compressor isn't any real hardship to be honest to deflate the system. As for setting levels, the car should automatically do this without the need for using ista. Just check that the level sensor arms are all pointing the same way (outwards kinda).

[Leslie]

Just remember if you put a hole in the car will drop like a ton of bricks so it's safer to vent at the compressor and pull the 40amp fuse as otherwise the compressor could start without warning when fitting crushing your hand!!

[asoni]

Thanks for the replies.

Just to confirm, I’d disconnect battery first so no chance of the compressor accidentally running.

Also the hole would be tiny so it should deflate slowly and controlled.

I realise it’s not a huge amount of extra work to access compressor but just wondering if there is any need to.

[mr angry]

I didn't disconnect the battery but unplugged the compressor when deflating the system by undoing one of the supply pipes

[henrym3]

At the end of the day you have to get to the top of the airbag to release the 2 clips that hold it in place, while there you undo the air pipe going to the bag. No need to disconnect the battery. To change key out of ignition, open boot lid. Once car has gone to sleep you can do all the work, after all compressor didn’t come on when airbags deflated overnight.

[asoni]

Just remember if you put a hole in the car will drop like a ton of bricks so it's safer to vent at the compressor and pull the 40amp fuse as otherwise the compressor could start without warning when fitting crushing your hand!!

The car will be jacked up so the suspension won’t be under any load, so surely nothing would drop when the airbags have been popped?

Also I’ll either pull fuse or disconnect batt so compressor doesn’t accidentally run.

I realise it’s not a huge amount of extra work to get to compressor but if it’s simply not necessary, it doesn’t make sense to do it?

[Leslie]

I did read it is easier to refit a bag if the line is off/loose at the compressor end or else the bag will not be that easy to pull down to clip onto the suspension arm due to not being able to fill with air and trying to return to its shape . There are videos on you tube showing how people have done it . Fuse out is safer as with mine the compressor will run with the key out as I've noticed before when getting out the car , all it would take is opening a door to bring the car back out of sleep mode.
You are of course right if its supported with the weight of the wheels then the wheel will only drop slowly , compressor is under drivers floor and say 8 screws approx to remove a cover, the 2 air lines go into a solenoid ( I had to change out my compressor over a year ago ) and all i did was drive the front wheel up on a concrete block to get enough clearance on my drive One is flat anyway so up to you really and I don't think you can take the line of the bag till its out but as I say never done it yet.

[asoni]

The guide I saw was basically:

- disconnect battery or fuse
- jack car and remove wheels
- slowly pop/cut air bags to let any air out
- twist to release airbag and gently pull until you can see the airlines at the top
- disconnect airline
- fit airline to new bag and refit

Sounds quite simple and makes sense which is why I'm going to try it without touching the compressor. Will post on here how I get on.

[Graeme]

I had both airt bags changed on my E70 and watched whilst it was done.

After jacking up the car and removing the wheels, removes the guard plates and locate the compressor - mine was under the driver seat (RHD 7 seater). Disconnect the air line to let down the bags. That way if something goes wrong you can refit them. Once a knife is put into them that's it - though it is the quickest way to deflate them.

Then twist them out of their bayonet fitting and disconnect the air lines from them. Refit the air lines. After fitting the guards underneath and wheels carefully lower the car and start the engine. It should settle to a level position.

There is no need to disconnect the battery as you'll have to recode it again. Just do the whole process with the ignition off.

Arnott do a pretty good You Tube video of the process though the compressor on their car is in a different place to mine.

[asoni]

Did the job today.

Went with the method above of just piercing the airbags, bit of a pop as the pressure released but worked a treat, didn’t need to touch the compressor.

Also didn’t need to disconnect battery or pull any fuses.

Getting the car onto axle stands was a nightmare due to rubbish jack, but these are bloody heavy things!

Anyway once jacked up and wheels off, replacing the bags literally took 10 mins a side. Extremely easy.

[asoni]

Looks like one of the bags is faulty as it’s going flat within 30 minutes of switching car off!

[mr angry]

Have you checked where the leak is coming from?

[asoni]

No but I didn’t touch anything apart from the airbags, and also that side was not leaking before with the old bag, it was the other side. I changed both however as that’s what’s advised.

Not sure what else could be leaking apart from the new bag itself.