chrisc

I have a 1960 B61 Mack. It is still all original. Old tractor protection valve is bad. Have not been able to find an original replacement. Was able to find a valve that is similar. Installed new valve, but now back brake chambers have no movement when engaged or disengaged. My Dad changed out the spring brakes to lock down brakes a few years ago. I am trying to use the original Mack air supply switch in the cab to engage the brakes. The original valve supplied the brake chambers with air supply. I have everything installed the same way, but I am wondering if this tractor protection valve might not work with the original equipment. Would be willing to change to a different valve if needed. Any help would be greatly appreciated.