Abstract: A hydraulic system for a vehicle suspension for a vehicle, the vehicle including a vehicle body and at least two forward and two rearward wheel assemblies, the vehicle suspension including front and rear resilient vehicle support means between the vehicle body and the wheel assemblies for resiliently supporting the vehicle above the wheel assemblies, the hydraulic system including: at least two front (11, 12) and two rear (13, 14) wheel rams respectively located between the wheel assemblies and the vehicle body, each ram (11 to 14) including at least a compression chamber (45 to 48) and a rebound chamber (49 to 52); wherein the compression chamber (45, 46) and rebound chamber (49, 50) of each said front wheel ram (11, 12) is in fluid communication with the rebound chamber (47, 48) and compression chamber (51, 52) respectively of a diagonally opposed said rear wheel ram (13, 14) to respectively provide two fluid circuits, each fluid circuit providing a front and back compression volume therein, the front compr

Abstract: A damping and stiffness system for a vehicle suspension system including at least two forward and two rearward wheel assemblies each associated with vehicle resilient support means (27-30) between a vehicle body and the wheel assemblies. The damping and stiffness system including: a wheel ram (11-14) with at least a compression chamber (45-48) between each wheel assembly and the vehicle body and a load distribution unit (76). The load distribution unit (76) includes two pairs of chambers (77-80), each chamber (77-80) being divided into front (89, 90) and back (91, 92) system chambers (which vary in volume proportionally and in opposite senses therein with piston motion) and the remaining pitch chambers (93-96) by interconnected pistons (81-84) supported therein. The compression chamber (45-48) of each wheel ram (11-14) is in fluid communication with a respective system chamber (89-92) wherein the vehicle is primarily supported by the vehicle resilient support means (27-30).