Yes, at least one of the front and rear valves have a tiny leak, so it's leaked front to back.
You can buy reconditioning kits from Rover Renovations in the 'states, though all you really need is some O rings. You can rebuild them yourself and whilst you have the control box off to do the ump you might as well remove the valve block completely, take it inside and inspect the O rings for perishing and splitting.
Just keep it all clean whilst you work