How do you bleed master cylinder on 98 gmc sierra 1500 pickup?

To bleed the master cylinder on a 1998 GMC Sierra 1500, start by ensuring the brake fluid reservoir is filled to the appropriate level. Then, locate the bleeder screws on the master cylinder, usually found on the side of the unit. Have a helper pump the brake pedal several times and hold it down; while they do this, open the bleeder screw to release any air and fluid, then close it before they release the pedal. Repeat this process until no air bubbles appear in the fluid, ensuring the reservoir remains full throughout.