Mounting Holes on 12 Inch by 2 Inch Break Assemblies 23-105 and 23-106

Question:

What is the mounting Bolt Circle diameter ?

asked by: Patrick G

Expert Reply:

The brake assembly mounting pattern is different than the wheel assemblies for trailers or cars. The difference being that the wheel has to rotate in balance to provide a smooth ride but the brake assembly is stationary with the drum and wheel spinning around it. Measuring between the bolt holes, the measurement is 2-1/8 inches on center for all bolt holes except the widest pair, on the bottom, which is 3 inches on center. The diameter of the holes in the backing plate for securing the brake assembly are .390 inch which is slightly larger than 3/8 inch. This means your mounting bolts should be either 3/8 inch or 10 mm, the 10 mm being the larger of the two.

expert reply by: Robert G