Richard,
I am presuming it pulls hard left only under braking and will track straight when driven? if this is the case and the only thing that has changed lately is the pads, then I fail to see how the brakes "are not the problem".
There are no doubt more technical experts in this forum than I, but I suspect the following possible issues;
- Lots of air in the right side brake line (or water, or other contaminant)
- A crimp in the brake line (possibly caused by poor handling when hoisting)
- A blockage in one side of the system (I think our cars isolate RF to LR and vice versa)
- A broken piston in the caliper (but I am sure the brake guys would have found that)
Good Luck with it... Keep clear of the "spares" car please
Cameron