Dorman W78978 Drum Brake Wheel Cylinder - Rear

Reliable Drum Brake Wheel Cylinder for Ford, Lincoln, Mercury

The Dorman W78978 drum brake wheel cylinder is engineered to restore proper brake hydraulics in select Ford, Lincoln, and Mercury vehicles. Designed with durable cast iron and precise specifications, this wheel cylinder ensures consistent braking performance for models like the Ford LTD Crown Victoria and Lincoln Continental.

Key Features of the Dorman W78978 Wheel Cylinder

• Constructed from cast iron for strength and durability
• Includes bleeder screw for easy brake system bleeding
• Bore diameter of 1 inch for accurate fit and function
• Brake component inlet thread size of 3/8-24 UNF
• Thread diameter measures 3/8 inch
• Package contains one drum brake wheel cylinder

Detailed Product Description

The Dorman W78978 drum brake wheel cylinder is designed specifically for brake hydraulics systems in Ford, Lincoln, and Mercury vehicles, including the Colony Park, Grand Marquis, and Marquis models. Its cast iron construction provides reliable resistance to wear and corrosion, essential for maintaining brake system integrity. The included bleeder screw simplifies maintenance by allowing efficient removal of air from the brake lines, which is critical for optimal brake responsiveness. With a bore diameter of 1 inch and standardized thread sizes, this wheel cylinder fits precisely within the brake assembly, ensuring consistent hydraulic pressure and smooth braking operation.

Common Applications and Problem Resolution

• Restores braking function in vehicles experiencing brake fluid leaks
• Replaces worn or seized wheel cylinders causing uneven brake application
• Addresses spongy brake pedal feel due to air in brake lines
• Corrects brake drag caused by faulty wheel cylinder pistons
• Prevents brake failure from corroded or damaged brake hydraulics components

Installation Notes and Tips

When installing the Dorman W78978 wheel cylinder, ensure the brake system is fully depressurized and the vehicle is securely lifted. Use the included bleeder screw to properly bleed the brake lines after installation to remove any trapped air. Verify thread compatibility with the brake component inlet to avoid cross-threading. Inspect brake shoes and hardware for wear during replacement to maintain overall brake system performance.

Quality Assurance and Warranty Information

Dorman manufactures the W78978 wheel cylinder to meet or exceed OEM specifications for fit, form, and function. The cast iron construction and precise machining contribute to long service life under normal operating conditions. This part is backed by Dorman's limited warranty, providing coverage against defects in material and workmanship for a specified period, ensuring confidence in your brake system repair.