For 2002 - 2005 GMC Envoy L6-4.2L, V8-5.3L; RWD & 4WD. For 2002 - 2005 GMC Envoy XL L6-4.2L, V8-5.3L; RWD & 4WD. For 2004 - 2005 GMC Envoy XUV L6-4.2L, V8-5.3L; RWD & 4WD. In power brake systems, which are found on virtually all vehicles, the brake booster is a component that multiplies the force the driver applies to the brake pedal.
