Dorman W37664 Drum Brake Wheel Cylinder - Rear

Reliable Drum Brake Wheel Cylinder for Chevrolet, Geo, and Isuzu

The Dorman W37664 drum brake wheel cylinder is engineered to restore proper braking function in select Chevrolet, Geo, and Isuzu vehicles. Designed with durable cast iron construction and precise dimensions, this wheel cylinder ensures consistent hydraulic pressure for safe and effective drum brake operation.

• Includes bleeder screw for easy brake fluid bleeding
• Brake line inlet thread diameter: 0.437 inches
• Brake component inlet thread size: 7/16-24
• Bore diameter of 0.688 inches for accurate fitment
• Constructed from cast iron for strength and durability
• Package contains one drum brake wheel cylinder

Durable Construction and Precise Specifications

The Dorman W37664 wheel cylinder features a cast iron casting material that provides long-lasting durability under demanding braking conditions. Its bore diameter of 0.688 inches and brake line inlet thread diameter of 0.437 inches ensure compatibility with the hydraulic brake systems of Chevrolet I-Mark, Geo Spectrum, and Isuzu models. The included bleeder screw simplifies maintenance by allowing efficient removal of air from the brake lines, although a bleeder screw cap is not included. This part is designed to meet the exact thread size of 7/16-24 for secure brake line connections.

Compatible Vehicles and Applications

This drum brake wheel cylinder is compatible with the following vehicles:

• Chevrolet I-Mark
• Geo Spectrum
• Isuzu models with matching brake specifications

It is intended for use in drum brake hydraulic systems to replace worn or leaking wheel cylinders, restoring proper brake function and safety.

Common Issues Addressed by This Wheel Cylinder

• Brake fluid leaks from the wheel cylinder
• Spongy or unresponsive brake pedal
• Uneven brake application or reduced braking power
• Corroded or damaged cylinder bore affecting brake performance
• Brake drag caused by sticking pistons within the cylinder

Installation Notes and Tips

When installing the Dorman W37664 drum brake wheel cylinder, ensure the brake system is properly bled using the included bleeder screw to remove air pockets. Verify thread compatibility with your vehicle’s brake lines (7/16-24 thread size) before installation. Inspect brake shoes and hardware for wear and replace as necessary to maintain optimal braking performance. Use appropriate brake fluid and follow manufacturer torque specifications for all fittings.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards for fit, form, and function. The W37664 wheel cylinder undergoes rigorous quality control to ensure reliable operation in your Chevrolet I-Mark, Geo Spectrum, or Isuzu vehicle. Please refer to Dorman’s warranty policy for specific coverage details.