SIPS airbag question

Post by **kranz** » 27 May 2016, 18:18

While foraging at the local auto graveyard I found a really nice, almost perfect leather passenger seat from a '98 S70. I'd like to use it for non-automotive purposes ( I found that these seats make great desk chairs when mounted on a proper pedestal). But I'd like to disarm the airbag lest someday down the road I receive a rude surprise. It has the round mechanical trigger, connected to the airbag and gas generator by some sort of cable.

Is it possible to safely disconnect the trigger from the cable and remove it?
Would that be sufficient to disarm the airbag or would the gas generator need to be removed as well?
Am I better off just leaving the red safety device in place, perhaps making it a bit more permanent and let sleeping dogs lie?

Thanks!

Post by **kranz** » 28 May 2016, 05:04

From reading the 850 airbag service manual it appears that the "cable" is actually a pair of tubes. The trigger sends a shockwave down the pair of tubes to activate a powder charge in the gas generators. Perhaps by severing this pair of tubes would prevent this from occuring and the trigger could be removed and disposed of.

Anyone have any experience with this?

Post by **MadeInJapan** » 28 May 2016, 07:34

I would hesitate!! I know slipping the plastic piece in the seat's side disables the airbag and you could just do that, but that's usually for the seat in and and out of the vehicle. I'm not sure if I want to be sitting around knowing there's a chance that the airbag could blow at some point. That said, not sure if severing the pair of tubes is a good idea either- that in itself could possibly set it off? If you could find a way to remove the little gas generator (or let it vent to the atmosphere) that might be the best answer but I have no idea on its location or how you might do that.

Post by **kranz** » 28 May 2016, 08:06

I just got back from a quick trip to the junk yard. Being careful to stay out of harms way, I tried severing those tubes on a rather well worn seat and did so without incident. They are hollow and made of some sort of plastic and were cut easily with a wire cutters. From looking at diagrams in the airbag service manual, the tubes run up the side of the seat backrest to where the airbag is located. It looks like the airbag and generators are either a single unit or co-located. The question is how inert are they with the trigger mechanism gone? Removing them would be best, but I'm not keen to start removing the leather covers.

Post by **Ozark Lee** » 28 May 2016, 10:21

That is a very good question and I don't know that I have an answer. Even with the trigger in place it is a bit of a challenge to get them to trigger when you want to do it. Robert has a video where he intentionally triggered one and it took numerous aggressive tries to get the job done.

...Lee

Post by **kranz** » 28 May 2016, 12:00

A while ago I replaced a seat in my '98 V70 and had to dispose of the original, so inspired by Robert's video, I thought I'd have a bit of fun with it. I used a wood splitting maul and it took a direct hit with a good bit of force to trigger it. According to the 850 airbag service manual "SIPS sensor does not sense deceleration or “G” forces. An impact of at least 6.6 ft/sec (2m/s) is necessary to trigger SIPS sensor. This prevents unnecessary activation by light blows from outside objects."

I found this comment about Volvo SIPS in the firehouse.com forum:

"...extrication techs should now be aware of the possibility of side impact airbags. Cutting the seat could also cut the two lines that go to the sodium azide as in the Volvo. If you have a fuel leak, there is the potential for a source of ignition if the rescue personnel accidentally activate the mechanical senorary unit. The two lines/tubing for the Volvo seat SIP are lined with cellulose nitrate which will initiate the sodium azide. If cut, you have vented the lines to a possible fuel vapor."

Apparently cutting those tubes releases some of these apparently volatile chemicals. Sounds like it could be a possible hazard.

Post by **abscate** » 29 May 2016, 05:33

I think for consumer use I would get the SIPS bags out of the seat. Maybe someone here can cut open a junkyard seat and give you the visual of where the bag sits and how you can unobtrusively remove it.

NaN3 is nasty stuff and you don't want this in your house. It's a white zoot suit job if the bag goes off. I don't how how the contact nature of it ages but most things that go boom don't age gracefully*

* with apologies to the institutions that granted me four college degrees in science