Replacing the rear wheel brake caliper (Opel Astra J)

The brake mechanism support is removed for replacement or repair, as well as to gain access to other units. The support can only be removed by partially disassembling it, removing the support and the pad guide one by one, since the support body blocks access to the upper guide mounting bolt, which makes it impossible to remove the entire assembly.

You will need: 15 mm socket head, 11 mm open-end wrench, 13 mm and 18 mm wrenches, wheel nut wrench, fine-nosed pliers, container for draining brake fluid.

To remove the caliper components individually, follow these steps:.

1. Loosen the nuts of the rear wheel attachment on the side of the replacement caliper, place the anti-rollback stops ("shoes") under the front wheels. Switch to I-gear in the manual transmission or move the selector lever of the automatic transmission to the "P" position (parking). Use the jack to lift the rear of the car, install it on secure supports, and remove the wheel.



2. Unscrew the bolt securing the brake hose tip to the caliper…



3. …and disconnect the hose from the caliper.



Plug the hose end holes in any way possible to prevent brake fluid from leaking out.



The hose tip is sealed with copper washers on both sides. Replace the washers with new ones each time you disassemble the connection.



4. Disconnect the release spring from the parking brake actuator lever…



5. …and from the bracket, then remove the spring.





6. Disconnect the rear parking brake cable end from the drive mechanism lever by removing the end from the slot in the lever.



7. Use pliers to squeeze the two locking clips of the parking brake cable housing stop…



8. …and remove the cable from the hole in the parking brake drive mechanism bracket.



9. Loosen the tightening of the lower guide pin mounting bracket of the caliper, holding the pin from turning with a second key..





10. …and unscrew the rack.



11. Loosen the upper caliper guide pin mounting bolt, holding the pin from turning with a second wrench..



12. …unscrew the bolt and remove the caliper.



13. Remove the inner…





14. …and the outer brake pads.



15. Loosen the two bolts of the lower and upper mountings of the shoe guide to the steering knuckle…



16. …unscrew the bolts…



17. …and remove the guide from the steering knuckle.



18. The second wheel support is removed in the same way.

19. Install the caliper components in the reverse order of removal. Before installing the shoe guide bolts to the steering knuckle, apply anaerobic thread locker to the bolt threads.

20. After installation, restore the brake fluid level in the master cylinder reservoir and bleed the air from the brake hydraulic system (see Bleeding the hydraulic brake system).

21. Adjust the parking brake drive (see Adjusting the parking brake drive).