Dorman M390175 Brake Master Cylinder

Reliable Brake Master Cylinder for Buick, Chevrolet, Oldsmobile, Pontiac

The Dorman M390175 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Buick, Chevrolet, Oldsmobile, and Pontiac models. Designed with precision, this master cylinder ensures consistent brake fluid pressure and reliable stopping power for vehicles like the Cutlass Supreme, Grand Prix, Lumina, Monte Carlo, and Regal.

• Master cylinder bore diameter: 24 mm for accurate fluid displacement
• Constructed from durable aluminum material for corrosion resistance
• Includes reservoir for brake fluid storage
• Equipped with a sensor to monitor brake system status
• Four outlets with secondary outlet thread diameter of 10 mm
• Rearward outlet size: M10 x 1.0 thread and unthreaded for versatile connection
• Package contains the master cylinder unit only; mounting hardware not included

Product Details and Specifications

The Dorman M390175 master cylinder features a 24 mm bore diameter, which is critical for maintaining the correct hydraulic pressure within the brake system. Its aluminum construction offers strength and resistance to corrosion, extending the service life of the component. The included reservoir allows for proper brake fluid containment and circulation, while the integrated sensor provides real-time monitoring of brake system performance. With four outlets, including a secondary outlet with a 10 mm thread diameter and a rearward outlet sized M10 x 1.0 and unthreaded, this master cylinder supports multiple brake line connections, ensuring compatibility with the hydraulic layout of the specified vehicle models.

Compatible Vehicles and Applications

This brake master cylinder is compatible with a range of GM vehicles, specifically:

• Buick Cutlass Supreme
• Chevrolet Lumina and Monte Carlo
• Oldsmobile Cutlass Supreme and Regal
• Pontiac Grand Prix

It is designed to replace the original equipment part and restore proper brake function in these models.

Common Issues Addressed by This Master Cylinder

• Brake pedal sinking or sponginess due to internal leaks
• Loss of hydraulic pressure affecting braking performance
• Brake fluid leaks from a worn or damaged master cylinder
• Warning light activation related to brake fluid level or pressure sensor
• Uneven brake application or poor stopping response

Installation Notes and Tips

• Ensure the brake system is properly bled after installation to remove air
• Verify compatibility with your vehicle’s brake line fittings and sensor connectors
• Mounting hardware is not included; reuse existing hardware or source separately
• Handle brake fluid carefully to avoid contamination and damage to painted surfaces
• Consult vehicle service manual for torque specifications and installation procedures

Quality Assurance and Warranty

Dorman manufactures this brake master cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction and integrated sensor contribute to reliable operation under normal driving conditions. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Refer to the product documentation for exact warranty terms.