Dorman 42102 Brake Master Cylinder Reservoir Cap Gasket

Brake Master Cylinder Reservoir Cap Gasket

Dorman 42102 is a rubber brake master cylinder reservoir cap gasket made to match the fit and function of the original gasket on specified vehicles. It is built for durable sealing performance in hydraulic brake systems, helping maintain a proper seal at the master cylinder reservoir cap.

Key Features

• Rubber construction for sealing performance and flexibility
• Matches original fit and function for specified applications
• Designed for hydraulic brake master cylinder reservoir caps
• Direct replacement for Dorman 42102
• Cross-references OE-style part numbers 4049658 and 6259163 for the same application

Detailed Description

This brake master cylinder reservoir cap gasket is a direct-fit sealing component for vehicles that use a hydraulic brake master cylinder reservoir cap. Dorman 42102 is engineered to restore the seal between the cap and reservoir, helping maintain brake fluid containment and consistent system integrity. It is a practical replacement for Chevrolet P30, GMC P3500, and Dodge D250/D350/W250/W350 applications listed in the fitment data, including hydraulic brake configurations.

Compatible With 1974-1996 Chevrolet and GMC P30/P3500 platforms, as well as 1986-1993 Dodge D250, D350, W250, and W350 models, this gasket supports OE-style service on a wide range of heavy-duty and van chassis applications. The Dorman 42102 part number is also useful when searching for a brake master cylinder reservoir cap gasket for Chevrolet P30 hydraulic brakes or GMC P3500 hydraulic brake systems.

What It Helps Address

• Brake fluid seepage at the master cylinder reservoir cap
• Loss of sealing at a worn or hardened gasket
• Reservoir contamination from a compromised cap seal
• Service issues caused by an aged hydraulic brake gasket
• Replacement needs during brake master cylinder maintenance

Installation Notes and Tips

Inspect the reservoir cap and sealing surface before installation. Clean the mating surfaces thoroughly, then install the gasket in the correct orientation so it seats evenly. Verify vehicle application by year, make, model, and brake configuration before ordering, especially on Chevrolet P30 and GMC P3500 hydraulic brake vehicles.

Quality Assurance

Dorman designs this gasket to match original fit and function and to deliver reliable performance in brake system service. The rubber material supports consistent sealing in the reservoir cap application.