Dorman M39809 Brake Master Cylinder

Reliable Brake Master Cylinder for Jeep CJ5 and CJ7

The Dorman M39809 brake master cylinder is designed specifically for Jeep CJ5 and CJ7 models, providing a durable and precise hydraulic braking solution. Crafted from cast iron with a 1.063-inch bore diameter, this master cylinder includes a reservoir and features two outlets for efficient brake fluid distribution.

Key Features of the Dorman M39809 Brake Master Cylinder

• Constructed from cast iron for strength and durability
• Includes reservoir for brake fluid storage
• Master cylinder bore diameter of 1.063 inches
• Two outlets with rearward outlet size 1/2-20 and secondary outlet thread diameter 9/16-18
• Compatible with Jeep CJ5 and CJ7 brake hydraulic systems
• Mounting hardware not included

Detailed Description of the Dorman M39809 Brake Master Cylinder

This brake master cylinder is engineered to meet the hydraulic braking requirements of Jeep CJ5 and CJ7 vehicles. The cast iron construction ensures long-lasting performance under demanding conditions. The 1.063-inch bore diameter is designed to provide consistent brake fluid pressure, while the included reservoir allows for proper fluid containment and monitoring. Featuring two outlets, the master cylinder supports dual-circuit brake systems, with a rearward outlet size of 1/2-20 and a secondary outlet thread diameter of 9/16-18, ensuring compatibility with original brake lines.

Common Applications and Issues Addressed

• Replacement for worn or leaking master cylinders in Jeep CJ5 and CJ7
• Restores proper brake fluid pressure and pedal feel
• Solves issues related to brake fluid leaks or reservoir damage
• Addresses brake system failure due to internal cylinder wear
• Improves braking reliability and safety on older Jeep models

Installation Notes and Tips

• Ensure brake system is properly bled after installation to remove air
• Verify compatibility with existing brake lines using outlet thread sizes
• Mounting hardware is not included; reuse original hardware or source separately
• Inspect brake lines and fittings for wear during installation
• Follow vehicle manufacturer torque specifications for mounting bolts

Quality Assurance and Warranty Information

Dorman manufactures the M39809 brake master cylinder to meet or exceed OEM standards for fit and function. The cast iron material and precise bore diameter contribute to reliable brake system performance. While mounting hardware is not included, the product is backed by Dorman's quality control processes. Please refer to Dorman's warranty policy for specific coverage details.