Combination valves are integral to modern automotive braking systems, merging the functions of proportioning valves and pressure differential valves into a single unit.

This design not only simplifies the braking system but also enhances safety by providing multiple functions in one component. Understanding the role of combination valves is essential for appreciating their importance in vehicle braking performance.

The primary function of a combination valve is to regulate brake fluid pressure between the front and rear brake circuits. By balancing this pressure, the combination valve helps prevent rear wheel lock-up during hard braking, similar to a proportioning valve. However, it also includes a pressure differential feature that monitors the brake system for any discrepancies in pressure between the front and rear circuits.

If a significant difference in pressure is detected—indicating a potential brake failure—the combination valve activates a warning light on the dashboard. This alert system is crucial for driver…