Q1. During a North Dakota CDL-B air brake pre-trip inspection, you find the parking brake does not hold the vehicle on a 20% grade. What is the required action before operating the vehicle?

• ○Repair or adjust the parking brake until it holds securely before driving.
• ○Use wheel chocks and proceed with caution on flat roads only.
• ○Operate the vehicle only downhill to reduce parking brake load.
• ○Rely on the service brakes to hold the vehicle when parked.