System Inoperative-Will Not Engage

Fuse blown. Brake or clutch switch circuit open. Defective engagement switch. Vacuum leak in servo and/or brake switch and connecting lines. Vacuum hose not connected to vacuum switch. Vacuum release switch misadjusted (always open). Crossed hoses at regulator. Open in wiring harness. Pinched or plugged hose supplying servo. Defective regulator.