People who are helping diagnose certain brake problem conditions - in particular a hard brake pedal - often suggest that you measure the vacuum pressure. The advice will sometimes mention that your engine must produce more than 18” of vacuum to give that nice easy pedal feel. In fact, we just provided that explanation in our recent Tech Talk article on diagnosing causes of a hard brake pedal.
Converting from manual to power-assisted brakes is a major upgrade and one of the most common projects that we discuss with customers. Due to the different size requirements for brake boosters and master cylinders, you may need some help sorting out the available options to optimize your vehicle’s brake system performance. That’s where the tech pros here at Master Power Brakes really shine.
Whether your vehicle has power or manual brakes, pedal ratio is important. If you are experiencing a hard pedal you should check your pedal ratio if you have converted from the vehicle’s OE set up. As a general rule, your pedal ratio should not exceed 6:1 for manual brakes with a 1” bore master cylinder and 4:1 for power brakes with a 1-1/8” bore master.