2010 Chevrolet Avalanche Owner's Manual - Page 201

Even when all of these things are working properly and the cover system is on, there may be some instances (heavy rains, automated car washes, etc.) when water can collect the following areas: E. Water drainage area around both sides of the box and the tailgate side F. Rear drains G. Cargo floor H. Cargo mat Maintenance and Cleaning To ensure that the water management system performs properly, be sure that the Midgate®, tailgate and cover system are fully closed and that all parts are clean and not blocked with debris. Follow the instructions given next in this section for the proper procedures on cleaning each item. A. Top drain grates B. Removable front drain grate (Midgate® drain gate) C. Side rail channels and catch cups D. Front drains 3-87