There are good schematics of the system and I think you can see almost everything for the rear axle under the trunk floor that comes off.

I had one axle system so didn't have height adjustment. Depending exactly where the leak I suspect it can hold at all heights. It's definitely tricky when a problem goes intermittent.

Too bad you didn't lift there trunk floor while it was hissing.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)