Brake question

[Tony Smith]

Originally Posted by Harry Moon

Wonder why even when they went to the big brakes on the front they used the smaller wheel cylinder even going so far as to use a different 1 3/8 than on the smaller front brake trucks.

All weight trucks use 1 3/8" bore wheel cylinders on the front, but their physical dimensions are different. Trucks with 6" hubs have 3.5" wide brake shoes, while 5" Hubs have 2" wide shoes.

To ensure the centre bore of the cylinder is aligned with the centreline of the shoe, the wider shoes have physically larger castings (the same casting as the rear brakes, but bored to 1 3/8").