2005 GMC Sierra 1500 Pickup Owner's Manual - Page 429

When to Check and What to Use The clutch master cylinder reservoir is located in the rear of the engine compartment on the driver's side of the vehicle. See Engine Compartment Overview on page 5-14 for more information on location. Engine Coolant The cooling system in your vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for five years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOL® extended life coolant. The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see Engine Overheating on page 5-37. A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will: Refer to the Maintenance Schedule to determine how often you should check the fluid level in your clutch master cylinder reservoir and for the proper fluid. See Owner Checks and Services on page 6-10 and Recommended Fluids and Lubricants on page 6-14. Give freezing protection down to −34°F (−37°C). Give boiling protection up to 265°F (129°C). Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning lights and gages work as they should. How to Check and Add Fluid The proper fluid should be added if the level does not reach the bottom of the diaphragm when it is in place in the reservoir. See the instructions on the reservoir cap. Notice: Using coolant other than DEX-COOL® may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50 000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX-COOL® (silicate-free) coolant in your vehicle. 5-35