2004 GMC Yukon Owner's Manual - Page 419

How to Check Power Steering Fluid Turn the key off, let the engine compartment cool down, wipe the cap and the top of the reservoir clean, then unscrew the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten it. Then remove the cap again and look at the fluid level on the dipstick. The level should be at the FULL COLD mark. If necessary, add only enough fluid to bring the level up to the mark. Windshield Washer Fluid What to Use When you need windshield washer fluid, be sure to read the manufacturer's instructions before use. If you will be operating your vehicle in an area where the temperature may fall below freezing, use a fluid that has sufficient protection against freezing. See Engine Compartment Overview on page 5-14 for reservoir location. What to Use To determine what kind of fluid to use, see Recommended Fluids and Lubricants on page 6-14. Always use the proper fluid. Failure to use the proper fluid can cause leaks and damage hoses and seals. Adding Washer Fluid Your vehicle has a low washer fluid message that comes on when the washer fluid is low. The message is displayed for 15 seconds at the start of each ignition cycle. When the CHECK WASHER FLUID message is displayed, you will need to add washer fluid to the windshield washer fluid reservoir. 5-41