Have a problem with a slight weep on one of the PAS pipes which is being fixed next week, but in the meantime have topped up the reservoir with half a litre of LDS fluid but there does not appear to be a Max or Min mark in the neck of the reservoir. I have just topped up and brought the level to the base of the small well or neck of the reservoir. Is this okay and or should I leave room for any expansion of the fluid during driving?

Can the steering be operated without the PAS i.e if the fluid drains completely?