Master Cylinders & Proportioning

Brake Master Cylinders, Proportioning Valves & Brake Boosters

The master cylinder is the hydraulic heart of the brake system - converting the driver's pedal effort into hydraulic pressure distributed to all four corners of the vehicle. The proportioning valve ensures that braking force is correctly distributed between front and rear axles, preventing rear wheel lockup under hard braking that would cause a loss of directional stability. And the power brake booster amplifies pedal effort through engine vacuum assistance, making the system manageable in normal use without requiring excessive pedal force.

With 77 products from Baer Brake Systems, our hydraulic brake component range covers master cylinders, adjustable proportioning valves, and power brake booster conversions for classic vehicle brake system builds and upgrades.

Master Cylinder Selection - Bore Diameter and Pedal Ratio

Master cylinder selection requires careful matching of bore diameter to the caliper piston area of the brake system, and the vehicle's pedal ratio and intended pedal feel. A master cylinder with a bore that's too small produces a firm, short pedal but requires excessive effort; too large and the pedal becomes spongy and travels excessively before generating useful pressure. For disc/drum combinations - front disc with rear drum - a dual-circuit master cylinder with different bore diameters for front and rear circuits provides appropriate pressure delivery to both system types.

Adjustable Proportioning Valves - Front-Rear Balance

An adjustable proportioning valve - particularly valuable on disc/drum combinations and vehicles with significantly modified weight distribution - allows the brake bias between front and rear to be set correctly for the specific vehicle rather than relying on a fixed valve calibrated for a very different configuration. Baer's adjustable proportioning valves are the professional solution for any disc brake conversion or performance brake upgrade where achieving correct front-rear balance is required for safe, consistent braking performance.

Power Brake Booster Conversions

For classic vehicles converting to disc brakes - where the substantially higher pedal effort of unassisted disc brakes would be unacceptable in daily driving - power brake booster conversion kits provide the vacuum-assisted pedal feel that makes a high-performance brake system comfortable to use. These conversions use the engine intake vacuum to multiply the driver's pedal effort, reducing the physical effort required to achieve strong deceleration to a comfortable level for road use.