1994 GMC Suburban Owner's Manual - Page 355

21. THERMOSTATICALLY CONTROLLED ENGINE COOLING FAN INSPECTIONAV - (If so equipped.) Inspect all hoses and ducts for properhook-up. Be sure the valve works properly. 22. EXHAUST PRESSURE REGULATOR VALVE INSPECTION* Check that the valve works properly. Correct any binding. Inspect hoses for cracks, chafing or decay. Replace parts as needed. 23. TIRE AND WHEEL ROTATION AND INSPECTION For proper wear and maximum tire life, rotate tires at thefirst 6,000 rniles (10 000 kilometers) for Schedule I (+) or 7,500miles (12 500 kilometers) for Schedule I1 (e) and then every 15,000 miles (25 000 kilometers) thereafter. Follow the instructions and patterns shown in Section 6. Check tires for uneven wear or damage. If irregular or premature wear is apparent, check wheel alignment. Also, check or damaged wheels. See "Tires" in the Index for more information. For dual wheels, whenever the vehicle, wheels, or fasteners are new, have the wheel fastener torque set at the first 100, 1,000 and 6,000 miles ( 160, 1600 and 10 000 km). Block the tires opposite those being removed to keep the vehicle from rolling. 24. DRIVE AXLE SERVICE? Chec.k readfront axle fluid level and add as needed. Check constant velocity joints and axle seals for leaking. 0 Locking differential - Drain fluid at first oil change and refill. Check fluid level and add as needed at subsequent oil changes. In dusty areas, or trailer towing applications drain fluid at every 15,000 miles (24 135 kilometers) and re.fiII. Standard differential - Check fluid level and add as needed at every oil change. In dusty areas, or trailer towing applications, drain fluid every 15,000 miles (24 135 kilometers) and refill. More frequent lubrication may be required on heavy-duty or off-road use. 0 0 * An Emission Control Service ANoise Emission Control Service VApplicable only to vehicles sold in the United States ?A fluid loss in these systems may indicate a problem. Have them inspected and repaired at once. 7-21