troopy pulling to the left

sounds like he got the wheel alignment wrong

Are the wheels spinning freely? You may have a seized brake caliper which is not an uncommon thing to find on any car. A new rotor would be thicker than an old worn one so unless he pushed the caliper pistons back into the caliper to make room for the rotor, it could be a very tight fit getting it in between the pads. If that is the case then the pad with the seized piston will be pressing firmly on the rotor and partially applying the brake on that side of the car only.

A problem like that should stand out a mile away to any mechanic but you never know.

Why did he use the old pads on a new rotor? That is not the usual thing to do.

The work that he did should not have change the wheel alignment

Is it tugging very hard to the left or more like drifting?
Is it doing this whilst driving, under braking or both?

Could he have left grease on the right rotor giving no right side braking?

Bob

Caster is supposed to keep the car running straight ahead, not cause it to pull to one side.

Look at this short DVD.Swivel Hub

Just before 3 minutes into it he lifts off the outer section of the swivel hub that the wheel is attached to. He then uses a punch to knock out the top and bottom bearing seats that the whole front wheel and hub assembly pivot from side to side on. It is the location of those bearings that gives you a caster angle.

If the car was at its correct ride height and you were to look at it from side on with the hub stripped down to this stage, you would see that the top bearing is slightly further back towards the rear of the car than the bottom bearing. This means a line passing through the centre of those bearings is not vertical to the road, it is leaning back slightly. That is your caster angle.

The wheel and its bearings are mounted on a stub axle that is swinging from side to side on this off vertical line so as you turn the wheels, the stub axle on one side lifts the wheel up slightly causing the car to drop a little while the wheel on the other side goes down a little causing the car to be lifted. You won't notice this while driving but if you turn around a corner then let go of the steering wheel, it will spin back to the straight ahead position. If the centre line of the bearings was vertical, there would be no change in the height of the car from side to side and the steering wheel would not self centre.

The more caster you have the harder it will be to turn the car off the straight ahead position and the quicker the steering will self centre.

The location of those bearings is fixed so the caster is not adjustable. There are kits available that can be fitted into the lower bearing to change its location by a type of eccentric cam. That is what your mechanic wants to install but it should not be necessary.

A mechanic working on wheel bearings or brakes is not going to touch those swivel hub bearings so the caster should not change. It the car was steering straight before the work was done then it should be doing the same after it.

hi
caster readings , no more than 1deg diff between Lhs and Rhs
vehicle will pull to the side with the most positive caster
If camber and toe are way different than spec they will pull
If he has rotated tyres this can cause pulling to one side
To verify this swap tyres left to right on the front
King pin bearings need doing at least every 100,000kms
Worn kingpin bearings do cause steering to drift

HI
BOB a3
The front end
Good practice is to set cruiser hub bearings up with a pull scale 4-6kg load.
Set the bearing shims stacks equally top and bottom . works 99% time
If u donot preload bearings correctly they will not last
To loose a bearings and cruisers wander all over the road at will .Vehicle has no directional confidence .

2nd
When the hubs /axles are pulled . Inspect where the inner seal runs on the axle .
99% chance they will be scored . Have these metal sprayed .

3rd not often done there are tools to set axle centre height . Its a pain to do . Only ever done when the vehicle has serious problems