Brake Question

[Pete::51]

While investigating a reduction in braking capacity today, I discovered my Fuzion 373 has manually adjusted brakes on the rear axle and self adjusting brakes on the front axle. Both are 7000lb. Dexter axles. This doesn’t make sense to me. As the brakes wear down the front axle will be doing more and more of the work. Has any one else seen that? Is this just another case of the factory grabbing whatever part is handy