[Steering & Suspension] steering tremor

[wd1506]

my 17 plate partner 100hp adblue van has a fault on the steering. it seems to have a tremor on the steering wheel at low revs which clears as the revs rise
this is at a stand still and when driving. if the van is jacked up and the steering is bled this fault clears for a short while. there are no leaks on the system whats so ever. there are no fault codes either. the only thing I have noticed is if the steering is turned from side to side whilst the engine is switched off it causes steering fluid to spill out of the fluid reservoir filler. this maybe normal  with the engine not running I don't know.
I hope someone can throw light on this fault.

[Sol]

Has it had work done recently that required the wheels to be moved when the engine was off? This scuppers the steering angle sensors for a while and it then vibrates as you turn left or right. It normally settles down after a few miles are driven / couple of days.

You can try running the engine and steering lock to lock several times, that is how to bleed it properly.

Not supposed to turn the steering on these if the engine is off, its got EHPS (electro-hydraulic power steering) not "conventional" power steering. The EHPS pump and angle sensors don't like it being moved when the pump is not running.