Q: Clutch pedal not engaging

Hello, you are correct that replacing the clutch master cylinder and slave is necessary as a pair. It would be helpful to know if it initially worked correctly after replacement. Since you have tried bleeding it, there is a chance the hydraulic system has an air pocket, and will need to bled again. You will probably need the aid of a mechanic, so the brake system can be bled by a professional. They will also be able to inspect the rest of the clutch system for proper operation. If the system is found to be bled correctly and the hydraulic is still not operating, the master or slave could have failed. If you would like assistance with this, have a certified mechanic diagnose your clutch system to see what issues have occurred.