Investigating the Life Cycle of the Air Bags on our two C Class w204s
I find that pre '92 it is between 10 & 15 years before they need replacing.
from then on ok for the Life of the Vehicle. My inquiry was in relation to the Curtin and knee Bags. The fronts were replaced by a recall this year.
. So I assume that the others are ok and safe. When I queried the Dealer earlier about the possible faulty Fronts, they denied that Mercedes had a problem. ???
Very early airbags had a “recommended” service life.
The cost was amazing, and caused a lot of backlash, and was only associated with European cars.
Some airbag recalls were for differing reasons, and not like the current Takata issues.
The Takata issue is where some of the nitrogen charge canisters rusts or corrodes and when the airbag is deployed the sudden change in pressure caused the nitrogen vessel to break, thus causing the shrapnel as we have seen in the news.
Even our Volvo, Mack & UD Trucks had some Takata airbag recalls here in Australia.
The percentage of corroded nitrogen vessels, are very low, but no one knows which vessels, or when they were made, so it’s like playing Russian Roulette.
All of our truck airbags replaced, had no issues with corrosion, but you just can’t take the chance.
As far as I know, most vehicles were affected in some way, including MB.
The manufacturer would have sent you a letter in the mail if you have had the car since new to let you know of the recall.
If it has been, the website will let you know.
ANYONE buying an airbag equipped car, should check this website before they buy.
Before I bought the Audi convertible, I checked it, and the website stated
“Your car is effected by the Takata airbag recall”
It then directed me to click on the Audi link which the site provided, and the Audi site told me the recall cad been completed.
When buying my W126's I was quite happy they did not have airbags fitted. I have no evidence for this, but I wasn't exactly comfortable with 30 year old airbags in the car, with 30 year old explosive charges etc. I wonder if they would even go off, or would they go off when they shouldn't? I've never heard anything one way or another on this, but did see a W126 at the wreckers yard that looked like a decently hard hit and an undeployed airbag.
The 88 and 89 models I owned at one point had the stickers in the door jam advising the bags should be replaced, which included the passengers bag on the 89 model.
Original airbags, were specifically for fairly severe full frontal impacts only.
The safety cell for occupants was the primary safety system used before this.
A safety cell is what is known as a “passive” safety device, an SRS system is known as an “active” safety system.
A passive system waits for something to happen passively, then when something happens, it can then do its job.
An active safety system (airbags, ABS, EBD, stability control etc) actively do things in the background to assist the driver to hopefully prevent the accident in the first place.
Now, modern electrics for airbags consist of micro gyroscopes and acoustic sensors or listening devices to “hear” the intensity of the collision and from what direction it came from.
Now we can even turn up or down the sensitivity at which an SRS system (seat belts or airbags) will or will not deploy.
The older systems incorporated mercury switches or switches that would simply be earthed by the severity of the impact, IE, if the front compacted enough, it would eventually flick the switch.
Original airbags were deployed by hydrocarbons as we used to fill aerosol cans with, and the bag itself was packed in corn flour which lubricated the bag and it’s folds so they don’t stick or grab while it was in its highly vacuum packed package.
That’s why they deploy with such huge force and speed, as you have such a massive positive pressure, acting upon a massive negative pressure.
Once a sensor has decided to deploy the airbag, the airbag is already fully deployed, and just starting its deflation cycle through their massive vents, before the occupant even starts to move forward (or sideways) and interacts with the bag its self.
Of course modern cars have all sorts of new systems that decide to interact even before things may happen, radar, cameras all that sort of stuff, will even start to tighten your seatbelts in an urgent situation, then back them off to a comfortable level when the emergency passes, and active braking and brake force assistance has been around for quite a while now, but the6 are all very good systems, that assist the driver.