Bonnet Gas Struts

[davidrew]

Just had the Zed (64 plate 19,500 miles) MOT and brake fluid change done at the local BMW and they have advised the Bonnet Gas Struts (B51.23.7.285.823) should be replaced as part of the service schedule as they are out of date. Also not covered on the BMW extended warranty.

I told them to leave it as the bonnet hasn't fallen on my head yet and I have it open once a week to check and charge the battery.

Seems like changing components for the sake of it unless any better qualified experts on the forum know otherwise.

Thanks for any advice.

[ihadablackdog]

I've got a 2011 2.0 and when its been into BMW in the past they've never mentioned this.

[B21]

I’d never heard of this one but yes it does exist..

I cross checked on my VIN number because often these procedures apply to only certain BMW models at certain times in certain markets.

However my 2012 MY 20i does have option S8TF so yes in theory they should be replaced as part of the maintenance program…

Strangely my 2011 MY 35is does not have S8TF in its VIN description...

[RobbiZ4]

...option S8TF so yes in theory they should be replaced as part of the maintenance program…

Yes, there is an expiry date on it as it's an active component and it has to be replaced on a regularly base. In Germany, the bi-annually TUEV checks will fail, if not replaced in time.

It's definitely NOT to safe your head UNDER the bonnet, it's to safe pedestrians.

[Pondrew]

So what about the explosive charges for the bonnet? Surely these will also have a 'shelf life'?

[ihadablackdog]

What is active pedestrian protection? Does it mean you can mow down pedestrians and they will be ok?

[B21]

I think on cars they design the charges so that their life equals /exceeds the anticpated life of the car..on aircraft, in part because they operate longer and its all super safety orientated they replace them typically around the 10-12 year mark..

[B21]

What is active pedestrian protection? Does it mean you can mow down pedestrians and they will be ok?

Er no..although they may be better off than if you had mowed them down at the same speed in an old Land Rover!

Small explosive charges at the rear of the bonnet pop the bonnet up in the event of a prang..raising the bonnet to act as a deformable area to take some of the G loading and spread the impact load..improving pedestrian survivability.

[Pondrew]

Small explosive charges at the rear of the bonnet pop the bonnet up in the event of a prang..raising the bonnet to act as a deformable area to take some of the G loading and spread the impact load..improving pedestrian survivability

Or in 'layman's talk'; it helps scoop people back onto the road in front to save them from damaging the windscreen.

[Argyll Andy]

I think on cars they design the charges so that their life equals /exceeds the anticpated life of the car..on aircraft, in part because they operate longer and its all super safety orientated they replace them typically around the 10-12 year mark..

Peter, Arnold said he had these as an advisory on his last MOT, carried out by BMW of course so could be a £££ making advisory

[Smartbear]

What is active pedestrian protection? Does it mean you can mow down pedestrians and they will be ok?

Er no..although they may be better off than if you had mowed them down at the same speed in an old Land Rover!

Small explosive charges at the rear of the bonnet pop the bonnet up in the event of a prang..raising the bonnet to act as a deformable area to take some of the G loading and spread the impact load..improving pedestrian survivability.

They may survive the initial impact courtesy of the BMW boffins intelligent design, but would quickly be beaten to death after the owner discovers the damage caused to the sacrificial bonnet
Rob

[Silverstar]

Unless it is a requirement for the MOT (as it is in Germany as pointed out by RobbieZ4) I would leave them as they are until I notice that they aren't doing their job of springing the bonnet up when you open it.

[B21]

I think on cars they design the charges so that their life equals /exceeds the anticpated life of the car..on aircraft, in part because they operate longer and its all super safety orientated they replace them typically around the 10-12 year mark..

Peter, Arnold said he had these as an advisory on his last MOT, carried out by BMW of course so could be a £££ making advisory

I think this is one of those rare occasions (for me) where I would just let this service requirement pass me by..

[B21]

What is active pedestrian protection? Does it mean you can mow down pedestrians and they will be ok?

Er no..although they may be better off than if you had mowed them down at the same speed in an old Land Rover!

Small explosive charges at the rear of the bonnet pop the bonnet up in the event of a prang..raising the bonnet to act as a deformable area to take some of the G loading and spread the impact load..improving pedestrian survivability.

They may survive the initial impact courtesy of the BMW boffins intelligent design, but would quickly be beaten to death after the owner discovers the damage caused to the sacrificial bonnet
Rob

Quite so…I had a slightly similar situation many years ago where a person with his back to a zebra crossing turned around and without looking walked onto the zebra as I was already moving slowly across it in stop / start traffic..

They literally fell across the bonnet and put a big dent in it (TR7)..

Trying to explain that away took some doing…

[Pondrew]

Unless it is a requirement for the MOT (as it is in Germany as pointed out by RobbieZ4) I would leave them as they are until I notice that they aren't doing their job of springing the bonnet up when you open it.

+1 on that.