Checking and Adding Fluid
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
For information on checking and adding fluid to the hydraulic booster system, refer to Checking and Adding Power Steering Fluid (With Hydroboost) or Checking and Adding Power Steering Fluid (Without Hydroboost) in Power Steering System.