Air Bag un-rolled - any advice?

A bit of a disaster just when things were going so well.

Today was supposed to be air bag replacement day.

Started on the right of the car and all went swimmingly.

Repeat for left side of car and all went well until it was time to put a little air in the bag.

Started engine, got back round to left of car and air bag was not inflating straight.

Got bact to drivers door window and turned engine off. By this time the bag had almost completely unrolled off its piston.

I am having a lot of bother trying to get it to roll bag on. I managed to get it part way and tried to install it again, but it just rolled right off again.

So, is there a knack to getting the airbag rolled back onto its piston, is it even possible, or have I just ruined an airbag at the start of the bank holiday with no chance of moving forward until next week?

And if the bag is ruined, is it possible to get a single airbag instead of a pair? They are Dunlop Pneurides.

Any advice would be greatly appreciated.

Disconnect the air feed to let it down then start again

Thanks Racandy, I'd already done that and got the air bag off.

My question was about how to get the air bag to roll back over its piston, as it was proving impossibly difficult to do by hand.

I have since answered my own question, and it wasn't a pretty or elegant answer, but it has worked.

I gripped the combined piston and the bit of rubber that I could get to roll back over it in the big bad vice and started to carefully knock the bottom of the piston with a rubber hammer.

After a few knocks, I would turn it around in the vice by 90 degrees and repeat, hitting it a little harder every few rotations, until I was within about 3cm of the 2 little rectangular slots near the base of the piston.

There is a bit of scuffing to the criss-cross patterning on the surface of the rubber, but nothing that would compromise its strength.

Then I put it back on the car and started the engine for 2 seconds. Then I checked the spring and made any fine adjustment before starting the engine for another 2 seconds. Repeat about half a dozen times and all went well.

I have since had a little test drive and measured the distance from wheel centre up to wheel arch on each side. They are within about 8mm, which I would say is acceptable, but am happy to be corrected.

Checking underneath the car, all looks identical on both sides.

The moral of this story is that it is easy to see what is going on when doing the drivers side air bag as you can watch what is happening to the new air bag with one hand on the ignition key. With the other side, one must be MUCH more carefull, just running the engine for a couple of seconds at a time and frequently checking the airbag.

Having the first one go in so easily on my first attempt at this job gave me a false sense of security and made me think all would be tickety boo with the other side, which it wasn't.

Thanks must go to Battenberg and his Definitive SLS Guide for giving me the confidence to have a go at this job, although I would recomend allowing half a day the first time its attempted by the non-profesionals amongst us.