Dorman M390056 Brake Master Cylinder

Reliable Brake Master Cylinder for Chevrolet Sidekick and Geo Tracker

The Dorman M390056 brake master cylinder is engineered to restore proper brake hydraulics for Chevrolet Sidekick and Geo Tracker models. Designed with precision, this aluminum master cylinder includes a reservoir and sensor to ensure consistent brake performance.

Key Features of the Dorman M390056 Brake Master Cylinder

• Master cylinder bore diameter of 0.875 inches for accurate hydraulic pressure
• Durable aluminum construction for corrosion resistance and longevity
• Includes reservoir for fluid storage and sensor for system monitoring
• Three outlet ports with a secondary outlet thread diameter of 10 mm
• Rearward outlet size specified as M10 x 1.0 with a thread pitch of 1.0

Detailed Product Description

This Dorman brake master cylinder (part number M390056) is designed specifically for use in Chevrolet Sidekick and Geo Tracker vehicles, ensuring compatibility and reliable fitment. The aluminum material provides strength while resisting corrosion, which is critical for brake system components exposed to moisture and brake fluid. The included reservoir allows for proper brake fluid containment, and the integrated sensor supports brake system diagnostics. With three outlets, including a secondary outlet with a 10 mm thread diameter and a rearward outlet sized M10 x 1.0, this master cylinder meets the precise hydraulic requirements of the specified models.

Common Applications and Issues Addressed

• Restores brake pressure and pedal feel in Chevrolet Sidekick and Geo Tracker
• Replaces leaking or damaged master cylinders causing brake fluid loss
• Resolves brake warning light issues related to sensor faults
• Addresses inconsistent braking performance due to worn internal components
• Prevents brake system failure from corroded or cracked master cylinders

Installation Notes and Tips

Installation of the Dorman M390056 brake master cylinder requires proper brake fluid handling and bleeding procedures to avoid air in the brake lines. Ensure the mounting surface is clean and free of debris before installation. Since mounting hardware is not included, retain or source the necessary bolts and fittings compatible with the Chevrolet Sidekick or Geo Tracker. Verify sensor connections are secure to maintain brake system monitoring functionality.

Quality Assurance and Warranty

Dorman manufactures this 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 operation. While specific warranty details are not provided, Dorman products typically come with a limited warranty covering defects in materials and workmanship.