Join Date: Aug 2010
Location: I would rather not say
Since you've already changed the pump relay, checked the wiring and changed the accumulator, I can't see how this could be anything but a knackered hydraulic pump. You've already had good indications of this earlier.
You cold try to bleed the system by releasing the bleeding screw on the return line back to the reservoir, run the pump for some seconds and then re-tighten and see if the helps. Giving the pump a good knock might also increase its lifespan a little longer.