off side pull

hi having recently fitted new front discs,callipers & pads every thing was fine for a couple of months, now when braking my disco pulls violently to the off side. having checked discs for rust patches to elliminate sticking caliper pistons, none visible.
the rear calipers & pads were replaced at the same time by the way. the tyres are BFG 235 70 16 with loads of tread and pressures are correct,
both swivel bearings have been replaced 12 months ago and were correctly pre-loaded. please any suggestions running out of ideas and pennies.

Stick your question in the Disco section and you should get a response.

cheers spidey kid done that i think ? been on the pop hands like cows tits