Hello, and welcome to JA!!!!! this vehicle uses park brake shoes inside the rear rotors!! the proper way is to adust the cleanerance between the rear e-brake shoes and the rotor. there is also one cable adjustment, that only removes slack in cable. tighten the cable wont help the e-brake to hold any better. I have included the instructions and pictures on what i am talking about!!!!! If you have any questions, please ask me to explain!!!!
Park Brake Adjustment Park Brake Shoe Adjustment
J 21177-A Drum-to-Brake Shoe Clearance Gage
Caution: Refer to Brake Dust Caution in the Preface section.
Important: The park brake shoes must be adjusted before the park brake pedal is adjusted.
Park Brake Pedal Adjustment
Important: Before you adjust the park brake, verify that the park brake shoes are adjusted to provide a clearance of 0.6604 mm (0.026 in).
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Tighten Tighten the nut to 3.5 N·m (31 lb in).
yes, you do have to remove the rear calipers and rotors to get to the adjusters. not one of gm's better ideas. there is also some updated parts for these e-brakes.
A rear parking brake retaining spring clip kit has been released for service. This kit consists of two parking brake hold down spring clips (2) and bolts (3).
Notice: Use J 46277 Rotor Removal Tool with J 6125-B Slide Hammer to remove the rotor from the vehicle. Place J 46277 between the rotor surfaces in the vent section of the rotor. DO NOT place J 46277 on the back side of the rotor surface, it may damage the rotor surface.
During rear brake rotor removal, it is possible to damage the parking brake shoe retaining spring clip. Order this new kit when replacement of the clips is required but the parking brake shoes do not require replacement.