Here's a hypothetical question

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JohnD
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Here's a hypothetical question

Post by JohnD »

But it's really a hydropneumatic question. My C5 is going to be loaded almost to its maximm payload in a couple of weeks and it will have to stay loaded for four or five nights. What's best? Leave the suspension at its normal ride height. Lower it down to the bottom. Or doesn't it make any difference?
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Chris570
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Re: Here's a hypothetical question

Post by Chris570 »

put it on it's belly, then there's no stress on the spheres.

i also do that with cars that will sit for a little bit of time as well as a sphere under no pressure (i.e. car on low) lasts a lot longer
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Mandrake
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Re: Here's a hypothetical question

Post by Mandrake »

Honestly, on the long life, low leakage multi-layer diaphragm spheres used on a C5 it's not going to make any meaningful difference in the life of the sphere whether you leave the suspension up or down with extra load in it, especially for just a few days. I wouldn't worry about it at all.

I left my Xantia on full suspension height (which is a harsher test for the spheres than just a heavy load) for nearly a week while it was off the road with a broken exhaust and didn't think twice about it.

Although the leakage rate of a sphere is less when the suspension is fully depressurised due to the metal dome in the middle of the diaphragm sealing against the bottom, the leakage when the sphere is operating at normal load and operating at increased load is the same - there is always equal pressure on both sides of the diaphragm, the only leakage is due to random diffusion through the diaphragm. It's not like a balloon or a tyre which has a pressure differential between both sides of the diaphragm material accelerating the leakage.

So there's no more benefit to depressurising the suspension with a heavy load than there would be with a normal load.
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