1997 GMC Suburban Owner's Manual - Page 315

Checking Brake Fluid What to Add When you do need brake fluid, use only DOT-3 brake fluid -- such as Delco Supreme 11 (GM Part No. 12377967). Use new brake fluid from a sealed container only. @ Always clean the brake fluid reservoir cap and the area around the cap beforeremoving it. This will help keep dirt from entering reservoir. the I You can check the brake fluidwithout taking off the cap. Just lookat the window on the brake fluid reservoir. The fluid levelshould be above MIN. If it isn't, have your brake system checked to see if there is a leak. After work is done on the brake hydraulic system, make sure the level is above MIN'and below the top of the window. With the wrong kind fluid in your brake of system, your brakes may not work well, or they may not even work atall. This could cause a crash. Always use the proper brake fluid. 6-33