150 GX Steering Wobble and Brake Issue ongoing- help please

[ozcruiser Lurker Find all posts View Profile Close ozcruiser]

I'm thinking your overheating your brakes and warping them do you have autobarn's in Spain.
Australia has a hot climate and we are known to strip our front rotor covers (backing plates) from the axel 's housing for cooling under heavy braking racing etc.

[JohnCW Lurker Find all posts View Profile Close JohnCW]

Is the mating surfaces of the discs rotor to hub flange clean?

THIS ........ The surface between the back of the rotor and wheel bearing hub needs to be spotlessly clean. Had this exact same problem on a Commodore. After machining the rotors everything would be fine for a while, then the disk runout would return. This happened a number of times till the back mating surfaces were were sanded down to shiny metal. Problem has never returned.