I have a 67 camaro that came originally with power drum brakes all around. I put discs on the front from a buick skylark. I put a new master cylinder and proportioning valve at that time. The brakes work fine. I have now put after market discs on the back and the brakes are not good. Do I need to replace the proportioning valve and the mater cylinder or just the proportioning valve alone? Or is it something else.
Any help would be greatly appreciated. Thanks