TM 10-3930-664-10 MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 16. PARKING BRAKE WILL NOT HOLD 4KRTFL Check parking brake cylinder on front axle for loose or missing mounting hardware. Notify Organizational Maintenance if mounting hardware loose or missing. 17. PARKING BRAKE WILL NOT RELEASE NOTE Parking brake is automatically applied when engine is stopped.  Engine must be running to release parking brake. Step 1.   Check for loose or broken wire connection at parking brake switch or parking brake solenoid. Report loose or broken wire connection to Organizational Maintenance. 3-11