HYDROPNEUMATIC/'HYDRACTIVE' SUSPENSION

 Certain Citroën models especially possess combined physical springs/dampers within a gas-filled sphere that has hydraulic fluid pumped into it under potentially lethal pressures that can exceed 2500psi. The gas leaks out over time, making the suspension go extremely hard. The greycoloured spheres (C5 and C6 models) last longer than the old green spheres but failure is more sudden. The spheres are removed by selecting full height on the suspension and loosening the spheres anti-clockwise by one turn. They can be very tight but some suppliers loan a special tool for the job, because a typical oil filter chain wrench is not strong enough. The suspension system should be depressurised completely, before the spheres are unscrewed. New spheres come with a seal that should be lubricated before fitting.