Air bags in the rear suspension

[iiyama]

How are they used? I thought they were there to level the van up? Or are they used for beefing the rear suspension up when loaded? or both? Help obviously required!!

[iiyama]

Thanks BB.

The rear suspension is basic leaf spring and shock, (base vehicle being a Peugeot Boxer chassis cab).

The air bags are mounted between the leaf spring and the chassis, no electronics that I know of.