Q: My ford Fairmond car brake works only by pressing hard on the brake pedal while driving to stop.

Hi there. First check the brake fluid and make sure that it’s full and clean. If the brake fluid is black in color and is the original brake fluid in the vehicle, I recommend flushing the brake fluid to remove any moisture from the system and fluid. This will help with the braking efforts. Then if you are still having issues, the master cylinder would need bleed and the system would need bleed for any air trapped in the system. If the fluid is changed and the system is bleed and you still are having a spongy pedal, then the master cylinder is leaking internally and it would need to be replaced. If the brake pedal is hard and very firm like when your engine is shut off, then check the vacuum lines from the engine to the brake booster. If the line is good, check the brake booster check valve for any leakage. If the line and brake booster check valve are good and sealed, then get a stethoscope (without the end only the tubes) and check for any hissing air around the clamped areas of the brake booster and by the firewall near the brake booster while the engine is running. If you hear a hissing noise when the engine is running, then the brake booster would need to be replaced. If you need further assistance with your brakes not working properly, then seek out a professional, such as one from Your Mechanic, to help you.