Squealing Avensis

[plasticvandan]

Hi all,was hoping someone might have a suggestion or some experience on a strange problem I'm having with my dad's 98 Mk1 Avensis.basically a few months ago it started squealing when on full lock,a typical loose fanbelt type noise. We changed the belt and noticed the fluid was very low,topped that up and it didn't really improve,would sometimes screech on start up but generally always on absolute full lock. After looking closer at it and removing belts one at a time, concluded the pump bearings were shot so managed to find a new one which I fitted today.the steering action is much smoother,bit the squeal remains! When it squeals the pump stops spinning briefly,as though it's got too much resistance for it to keep pumping against.alternator belt (which comes off crank and drives the water pump and Pas pump (shares the same pulley) seems fine.we have almost run out of ideas on this one.i did think maybe there was air in the system from when it ran low but there is no bleed screws etc,just says to turn the steering a few times to get any air out. Any thoughts?

[Asimo]

On full lock the load on the pump is at maximum, the oil pressure from the pump being limited by a relief valve.

The pump should not stall though.

Is the belt  worn out by the squealing and is it correctly tensioned?  Check it fits the pump pulley ok and is not bottoming between the pulley sheaves. 

 

[plasticvandan]

I think if anything the belt is on the right side,it was new and has maybe done 200 miles.i will give it a closer.inspection tomorrow

[sloth]

its the pressure releif in the rack. it jams and stalls the pump.