95 Granvia Steering

[Dagod]

Any advice appreciated

I have a 95 2.7 Granvia.

The steering goes intermittently hard, as if you are driving with 2 flat tyres, can also descibe it whilst driving.... if you are parked up and trying to turn the wheel againt the curb(if that makes sense?)

some journeys are fine, and then the next its back 

Ive had 2 new front tyres, wheel alignment & Tracking, renewed the power steering fluid

thanks in advance