Brake problems: New pads, rotors, master cylinder and booster, 4 big jugs of new fluid… pedal to the floor right after starting and sometimes very, VERY hard pedal with no breaking. 19″ of vacuum at idle then fluctuates between 13″ after throttle let off to 23″ on reeve.
RESPONSE
Did you bench bleed the master cylinder before installation? Did you bleed the brake system to get all the air out? It sounds like you did not if the pedal is going to the floor. Pumping the brake pedal will get you a hard pedal and no braking if there is air in the system. Air in the system is the most common issue with brake problems after the system has been open.
Brake pedal feel is firm, but brakes lack sufficient stopping power or fade
- Check the operation of the brake booster and brake booster check valve. Replace worn or failed parts.
- Check brake linings and brake surface areas for glazing and replace worn or damaged parts.
- Check for seized hydraulic parts and linkages, and clean or replace as needed.
Source: Brakes