Many builders report that the most overlooked step when upgrading brakes on a classic car or truck is
properly matching the master cylinder and proportioning valve to the new brake system.
properly matching the master cylinder and proportioning valve to the new brake system.
Many enthusiasts upgrade to disc brakes or larger rotors but keep the original drum-style master cylinder or skip adjusting the proportioning valve. This mismatch can lead to:
- Poor pedal feel
- Unbalanced braking (especially front/rear bias)
- Premature lockup or fading
- Unsafe stopping performance
When upgrading brakes, always make sure to use a master cylinder with the correct bore size and a proportioning valve suited to your front/rear setup (disc/drum or disc/disc). It's a small detail that makes a huge difference in how your classic performs and stops.
Builders, what step tripped you up? Let us know below.