2007 GMC Sierra 1500 Pickup Owner's Manual - Page 625

(k) Inspect system. Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properly. (m) Change automatic transmission fluid and external transmission filter if the vehicle is mainly driven under one or more of these conditions: − In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. − In hilly or mountainous terrain. − When doing frequent trailer towing. − Uses such as found in taxi, police, or delivery service. (n) Vehicles with diesel engine or with GVWR above 10,000 lbs (4 536 kg) only: Inspect shields for damage or looseness. Adjust or replace as required. This is a Noise Emission Control Service. Applicable to vehicles sold in the United States and recommended for vehicles sold in Canada. (p) If you drive regularly under dusty conditions, inspect the filter or change indicator (if equipped) at each engine oil change. (q) Visually inspect belt for fraying, excessive cracks, or obvious damage. Replace belt if necessary. Owner Checks and Services These owner checks and services should be performed at the intervals specified to help ensure the safety, dependability, and emission control performance of your vehicle. Your GM Goodwrench® dealer can assist you with these checks and services. Be sure any necessary repairs are completed at once. Whenever any fluids or lubricants are added to your vehicle, make sure they are the proper ones, as shown in Recommended Fluids and Lubricants on page 629. At the First 100, 1,000 and 6,000 Miles (160, 1 600 and 10 000 km) Check dual wheel nut torque. For proper torque, see Capacities and Specifications on page 609. 625