Dorman M630040 Brake Master Cylinder

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

The Dorman M630040 Brake Master Cylinder is designed to restore proper brake hydraulics in select Buick, Cadillac, Oldsmobile, and Pontiac models. Engineered with an aluminum body and integrated reservoir, this master cylinder ensures consistent brake fluid delivery and pressure for safe stopping performance.

• Master cylinder bore diameter: 1 inch for precise hydraulic control
• Constructed from durable aluminum material for corrosion resistance
• Includes reservoir for brake fluid storage and management
• Equipped with sensor to monitor brake system status
• Two outlets with rearward outlet size M14 x 1.5 and 14mm secondary outlet thread diameter
• Thread pitch of 1.5 for secure fitting
• Package contains the master cylinder only; mounting hardware not included

Detailed Product Description

The Dorman M630040 brake master cylinder is specifically engineered for compatibility with Buick Aurora, Cadillac DeVille, Oldsmobile LeSabre, and Pontiac Bonneville models. Its 1-inch bore diameter provides accurate hydraulic pressure control, essential for effective brake system operation. The aluminum construction offers enhanced durability and resistance to corrosion, extending the service life of the component. This master cylinder includes an integrated reservoir to maintain proper brake fluid levels and a sensor to provide feedback on brake system conditions. Featuring two outlets with a rearward outlet size of M14 x 1.5 and a secondary outlet thread diameter of 14mm, it ensures proper fluid distribution to the brake lines. The thread pitch of 1.5 guarantees a secure and leak-free connection during installation.

Common Applications and Issues Addressed

• Restores brake hydraulic pressure in Buick Aurora, Cadillac DeVille, Oldsmobile LeSabre, and Pontiac Bonneville
• Replaces worn or leaking master cylinders causing brake fluid loss
• Solves spongy or unresponsive brake pedal feel due to internal seal failure
• Addresses brake warning light activation related to sensor faults
• Prevents brake system failure caused by reservoir damage or contamination

Installation Notes and Tips

• Ensure brake fluid reservoir is properly filled before installation
• Bleed the brake system thoroughly after installation to remove air
• Verify thread pitch and outlet sizes match vehicle specifications for proper fit
• Use appropriate tools to avoid damaging aluminum surfaces during installation
• Mounting hardware is not included; reuse existing hardware or source separately

Quality Assurance and Warranty

Dorman manufactures the M630040 brake master cylinder to meet or exceed OEM specifications for fit, form, and function. The aluminum construction and integrated sensor contribute to reliable brake system performance. While mounting hardware is not included, the product undergoes quality checks to ensure durability and compatibility with specified Buick, Cadillac, Oldsmobile, and Pontiac models. Warranty details should be confirmed with the distributor or manufacturer.