855 airbag service vs change

The service label on my 855 TDI 1996 tells me to have the SIPS and SRS airbag systems serviced or exchanged in April 2007. What exactly would "service" mean? What is reasonable and economical to do?

Viktor

Reply to
viktor weisshaeupl
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Volvo has extended the lifetime of the airbags, so far by 5 years or more, cant remember exactly.

Greetings Niels

Reply to
Niels Bengaard

This is an administrative problem, IMO. There is no way to test airbags for deterioration, but many car mfrs wanted to demonstrate due diligence on recommended maintenance so they recommended "inspection intervals" - perhaps in the hope there would be more info when the time came. Now the time has come. I don't believe there are enough air bag failures to identify a reasonable life expectancy. Finally, replacement of air bags is unreasonably expensive for any car old enough that it is an issue.

About all you can do is ensure any SRS warnings are taken care of if they pop up and enjoy your car.

Mike

Reply to
Michael Pardee

Are there even any documented airbag failures? I know I saw a clip one point where they tested a very early airbag in a 20+ year old car and it still deployed as designed.

Reply to
James Sweet

I'll second this. Prolonged for five years, AFAIK.

Regards, Torsten

Reply to
Torsten Beekhuis

"Michael Pardee" schrieb im Newsbeitrag news:Z_adnRgI4IkrPL_bnZ2dnUVZ snipped-for-privacy@sedona.net...

Interesting. One of the reasons why I switched from the 745 to the 855 were the airbags. I did not want to give the retirement insurance the chance to collect my money without having to pay anything :-) . Do the airbags work with dry explosives ignited by electricity? Or are there pressurized gases which are released? If there are any electric contact problems, e.g. at the steering wheel air bag, I expect the SRS warning system to report that?

Regards

Viktor

-- The e-mail in the header is never read personal e-mail vikwei at gmx dot at

Reply to
viktor weisshaeupl

An airbag actuator is a sealed propellant charge, not an explosive. They are ignited electrically and burn very fast to create gasses which inflate the bag. The gasses are vented almost immediately, still hot enough to cause serious burns (as a co-workers' spouse found out the hard way).

Yes, it'll be checking continuity and will generate a fault if it's not within a certain range.

Gary

Reply to
Gary Heston

They use a chemical charge which is usually sodium azide and an oxidizer, it's an explosive in the same way as black gunpowder in that if you put it in a sealed enclosure it will explode but it's really just burning very rapidly. In the case of an airbag, the expanding gasses fill the bag. It's ignited electrically.

Those things are scary to me, even just on this group there have been a couple reports of accidental airbag deployments when water got in the control box and plenty of people are injured when the bag deploys while their arms are in the way. You also have to be very careful working on airbag equipped cars and always disconnect the battery before messing around. In theory the SRS warning will detect faults, in practice there's so many ways for a circuit to malfunction that you can never predict them all. Personally I always wear my seatbelt, make sure it's properly adjusted, pay attention, and drive defensively. I won't buy an airbag equipped car, and if I did, I'd certainly disconnect or remove it.

Reply to
James Sweet

"James Sweet" schrieb im Newsbeitrag news:sKsWh.624$YI1.416@trndny04...

I have looked the stuff up myself now. The oxidizer is potassium nitrate, the resulting compounds are nitrogen gas, which fills the bag after ignition within

20-40 msec, and potassium and sodium oxide. Newer air bags work with an additional compressed gas container.

Still an arm injury is usually less life threatening than the injuries which the airbags can prevent. The energy is dissipated over a bigger area and time. When wearing only seat belts, the pressure of the belt over a smaller area and the head banging around can cause nasty injuries to the big vessels behind the clavicle and in the neck.

Not turning off brain.exe is always important, I proceed as you except with the air bags now. Of course the seatbelt has always to be used and the airbag does not replace it, it is an additional protection. Statistics state that the airbags reduce letality of car accidents over the protection given by seat belts alone, so I believe in it. Even a seat belt can be lethal in an accident, but these cases are very rare, in most instances it protects, so I do also use it even knowing that there is a little chance that it kills me. Hopefully I will need neither of them.

Regards

Viktor The e-mail in the header is never read personal e-mail vikwei at gmx dot at

Reply to
viktor weisshaeupl

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