These calipers are intended for use on 12” wheels with 8.4”diameter solid discs.
When fitting vented discs, spacers are required to fit between the two halves (Spacer kit C-AJJ4021) If using vented discs the drive flange must also be changed to the relevant type NAM6450F. When fitting the calipers ensure the wheel studs are sitting flush in the flange or disc as they should be in standard form and not fouling in any way.
CHECK that the disc is central in the caliper slot and not fouling anywhere when bolted up. Any realignment can be made using 3/8”ID washers.
BEWARE there are some rogue hubs where the bolt holes for the caliper are slightly out of alignment which detrimentally affects the positioning of the calipers, creating insufficient clearance between the disc and caliper. Turning the disc down by 1mm or so, will help eliminate this problem. The calipers are left and right handed. Please ensure they are installed with the bleed screws in the vertical position( i.e at the top)