C5 X7 - A loud bang and the right side fell

[Stickyfinger]

This "guessing game" is silly......the car needs to put on a ramp and inspected....

Having a list of potential suspects is not "silly". You do you, if you have nothing to contribute besides name calling I would recommend you go somewhere else.

it is "Something at the front".....that is as accurate as it will get.
One random guess will be correct, you will know which one when you get it on a ramp to check it....

List of suspects....
Front Suspension part (list random part)
Sphere

I would recommend a blindfold & pin to stick in your image of the front suspension...........

[steveclv]

Almost certainly the right hand sphere has failed. As the gas pressure reduces, a spiked ring inside penetrates the rubber diaphragm causing it to 'explode'. LDS leaks into the sphere and that corner of the car drops. At the lowest suspension setting you should see LDS at the bottom of the tank - you don't because the LDS is now inside the sphere.
There is no leakage from the car when this happens, just a loud bang and the corner of the car drops.
I suggest that you change at least both front spheres.

Regarding the height - the height sensor is on the left hand side - it does not measure both sides.

[aerodynamica]

Almost certainly the right hand sphere has failed. As the gas pressure reduces, a spiked ring inside penetrates the rubber diaphragm causing it to 'explode'. LDS leaks into the sphere and that corner of the car drops. At the lowest suspension setting you should see LDS at the bottom of the tank - you don't because the LDS is now inside the sphere.
There is no leakage from the car when this happens, just a loud bang and the corner of the car drops.
I suggest that you change at least both front spheres.

Regarding the height - the height sensor is on the left hand side - it does not measure both sides.

Sorry, the height sensor measures the both sides by averaging the two sides by the position of the anti roll bar. The left side location of the height sensor is incidental because the clamp it attaches to on the anti roll bar is at or near the middle of the anti roll bar. Same at the rear. It has been this way since the very first DS in 1955.

And further, as had been said: a failed sphere on one side will not cause the car to drop on one side. The fluid pressure is equalised across the axle Left to right so any loss of gas pressure in a sphere (whether sudden or not) will affect both left and right side hight. That is until the height adjusting system detects a height change and adds more fluid to raise the height.

I really think this car in the o.p has suffered a physical, structural failure. Just remains to find out what it is.

[n0stra]

Almost certainly the right hand sphere has failed. As the gas pressure reduces, a spiked ring inside penetrates the rubber diaphragm causing it to 'explode'. LDS leaks into the sphere and that corner of the car drops. At the lowest suspension setting you should see LDS at the bottom of the tank - you don't because the LDS is now inside the sphere.
There is no leakage from the car when this happens, just a loud bang and the corner of the car drops.
I suggest that you change at least both front spheres.

Regarding the height - the height sensor is on the left hand side - it does not measure both sides.

Sorry, the height sensor measures the both sides by averaging the two sides by the position of the anti roll bar. The left side location of the height sensor is incidental because the clamp it attaches to on the anti roll bar is at or near the middle of the anti roll bar. Same at the rear. It has been this way since the very first DS in 1955.

And further, as had been said: a failed sphere on one side will not cause the car to drop on one side. The fluid pressure is equalised across the axle Left to right so any loss of gas pressure in a sphere (whether sudden or not) will affect both left and right side hight. That is until the height adjusting system detects a height change and adds more fluid to raise the height.

I really think this car in the o.p has suffered a physical, structural failure. Just remains to find out what it is.

I'm no mechanic but I do have some physics knowledge and it would be strange and damaging if the suspension work, as you claim , in tandem. That would mean the suspension would act the same way when only one wheel went into a hole, making the whole car jump.

After reading up the last couple of days it has been claimed, by way more knowledgeable people than me in this and other forums, that the later hydraulic systems are one way, not sircular, and that a leak or damaged to the system does not empty the other parts of it, unlike the older versions.

The claim is that the system in total has lost available lds fluid, but mostly on the part where the "leak" came about.

This supposed "structural damage" you keep talking about seems way more far fetched considering there are no symptoms what so ever supporting them (no visible damage, no leaks, the hydraulic system still functions, the pump works, there are no relevant errors in diagbox supporting this, and so on). Your hypothesis also don't explain where the loss in lds fluid has disappeared , while the blown sphere gives a total loss of 0,5 liters and fits perfectly.

[aerodynamica]

Well. Good luck with the investigation

[steveclv]

We will just have to wait and see what transpires

[n0stra]

I appreciate the input and i guess we will have to just see. Getting a proper tool to get the old sphere loose today. Hoping for the best. I'll keep you updated no matter what.

[aerodynamica]

Well it would be good to learn what's going on for future preservation of C5s. My C5 is 17 years old now and when I compare it to my first CX that was 19 at the time, the C5 looks half as old. But it can still have scary failures. Even if it doesn't have holes of rust you can put your hand through like that CX : )

[steveclv]

Don't forget that unless you depressurise the system it will be 'almost' impossible to remove the sphere. Once depressurized with Diagbox then a good chain wrench and a 1m piece of scaffold pole will loosen them

[n0stra]

Don't forget that unless you depressurise the system it will be 'almost' impossible to remove the sphere. Once depressurized with Diagbox then a good chain wrench and a 1m piece of scaffold pole will loosen them

Got the old one off and "new" one on. Unfortunately forgot the part where pressure is needed to get the pump running properly again. Found a old cap that fits, will try to get a bike vent attached to it tomorrow and see if I can generate the necessary 0.5 bars.

[Hell Razor5543]

You can, if you are careful (and are healthy), BLOW at 0.5 BAR. Clean the reservoir thoroughly where the cap screws on, seal your lips around it, and blow hard.

[n0stra]

You can, if you are careful (and are healthy), BLOW at 0.5 BAR. Clean the reservoir thoroughly where the cap screws on, seal your lips around it, and blow hard.

Tried that, without luck unfortunately. Seems I just don't blow enough

[Hell Razor5543]

You can, if you are careful (and are healthy), BLOW at 0.5 BAR. Clean the reservoir thoroughly where the cap screws on, seal your lips around it, and blow hard.

Tried that, without luck unfortunately. Seems I just don't blow enough

Did you have the suspension set to HIGH? If the suspension pump is not running you will not be able to prime it.

[aerodynamica]

You can, if you are careful (and are healthy), BLOW at 0.5 BAR. Clean the reservoir thoroughly where the cap screws on, seal your lips around it, and blow hard.

I did this and it does work. Make sure you clean any lds off the area though because it tastes...... nice....


.. I prefer LHM

If the pump is running and you apply pressure to it via blowing or adapted cap with bike valve, you will hear a change in the pump sound as it primes.

[aerodynamica]

.. sometimes the pump will run too long and will time out but it will start again after a 'rest"