Dorman M630035 Brake Master Cylinder

Reliable Brake Master Cylinder for GM Trucks and SUVs

The Dorman M630035 Brake Master Cylinder is engineered to restore proper brake hydraulics for select Cadillac, Chevrolet, and GMC vehicles. Designed 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: 37 mm for precise hydraulic control
• Durable aluminum construction for corrosion resistance
• Includes reservoir and sensor for complete brake system integration
• Two outlets with secondary outlet thread diameter of 0.5 inches
• Rearward outlet size: 1/2-20 for secure brake line connections
• Compatible with multiple GM models including Silverado, Sierra, Tahoe, Yukon, Escalade, and Avalanche

Product Details and Specifications

The Dorman M630035 master cylinder features a 37 mm bore diameter, which is critical for maintaining the correct hydraulic pressure in the brake system. Constructed from aluminum, this part offers enhanced durability and resistance to corrosion compared to traditional cast iron units. The included reservoir allows for proper brake fluid storage and monitoring, while the integrated sensor supports brake fluid level detection to alert drivers of low fluid conditions. With two outlets and a secondary outlet thread diameter of 0.5 inches, this master cylinder supports dual-circuit brake systems commonly found in heavy-duty GM trucks and SUVs. The rearward outlet size of 1/2-20 ensures compatibility with factory brake lines for a secure fit.

Compatible Vehicles and Applications

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

• Cadillac Escalade and Escalade EXT
• Chevrolet Avalanche 1500 and 2500
• Chevrolet Blazer, Silverado 1500, 1500 HD, 2500, 2500 HD, and 3500
• Chevrolet Suburban 1500 and 2500
• Chevrolet Tahoe
• GMC Sierra 1500, 1500 HD, 2500, 2500 HD, and 3500
• GMC Yukon, Yukon XL 1500, and Yukon XL 2500

Common Brake System Issues Addressed

• Brake pedal sinking or sponginess due to master cylinder wear
• Brake fluid leaks from a damaged or corroded master cylinder
• Brake warning light activation caused by faulty fluid level sensor
• Uneven braking or reduced stopping power
• Brake system failure from internal seal deterioration

Installation Notes and Tips

• Ensure brake fluid reservoir is properly filled and free of contaminants before installation
• Bleed the brake system thoroughly after replacing the master cylinder to remove air
• Verify compatibility with your specific vehicle year and model before purchase
• Use appropriate tools to avoid damaging outlet threads during brake line connection
• Check sensor wiring connections for proper brake fluid level monitoring

Quality Assurance and Warranty

Dorman manufactures the M630035 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 specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Refer to product documentation for exact warranty terms.