Warped rotors

[gruffly]

Hi again folks! My 96 2.0 vento gl has warped three sets of front brake rotors this year for no apparent reason. Two cheap sets and now a pair of brembos. I fitted new pads at the first and third times, the pistons move smoothly and the callipers move easily on the guide pins. The disc / hub mating surfaces were scrubbed clean and it hasn't been caned.
Is there anything I haven't done that i should've? Would I be better off having them skimmed true so they don't warp again?
Again all help would be gratefully recieved, thanks in advance

[zollaf]

any chance of a bit more info? obviously your car has a problem as it shouldnt warp discs like that. are you sure the discs are warped ? have you checked them for runout ? and anything else thats been done or noticed.

[Crasher]

Remove the discs and check the hubs for runout.

[gruffly]

I'll have to go buy a runout guage and check, there is pulsing through the pedal on braking and distinct tight spots when turning the jacked up wheel. Wierd thing is it's both sides. Change the rotors and all is fine again for a couple hundred miles then it comes back.
Nothing else out of the ordinary that I can think of

[Crasher]

That will be a warped hub or two or even a distorted wheel mounting face.

[gruffly]

Pants! I'll check once I have the tool but if it is can it be machined or is replacement the only option? Any idea what could've caused it as it only became aparent after changing worn out rotors which had given perfect trouble free service.

[Crasher]

No, new wheel bearings and hubs-a job that has to be done in a press.

[gruffly]

Hmm, i had the bearings done about a year ago so I'll be slightly peeved if that's the case.
We'll see what the runout guage says, tomorrow with a bit of luck. Thanks for the advice