Brake Master Cylinder for 1984-1988 Toyota 4Runner & More - Dorman M39500

Turn brake-pedal effort into hydraulic pressure with the Dorman Brake Master Cylinder M39500, a direct-fit 4Runner master cylinder for the 1984-1988 Toyota 4Runner that also fits the 1979-1988 Toyota Pickup, all engines. Dorman precision-engineers this unit to match the original master cylinder's design, function and performance, and builds it from new, high-quality materials.

• Precise replacement: the cast iron cylinder housing is built to match the casting material of the original part, for similar performance.
• Durable design: every rubber component uses a high-quality EPDM compound that resists glycol-based brake fluid.
• 100% new: made entirely of new materials.
• Strict specifications: made to meet rigorous SAE International standards.

Specifications: 0.813 in bore diameter. It has two outlets: the secondary outlet has an M10 x 1.0 thread, and the primary outlet has a 1 mm thread pitch. The reservoir and sensor are included. Mounting hardware is not included, so check the vehicle service information for the correct fasteners and whether they can be reused. Country of origin: Taiwan.

Signs a master cylinder may need replacing include a soft or sinking brake pedal and brake fluid leaking at the master cylinder. Diagnose the brake system before replacing parts, and bleed the brakes after installation as the service procedure directs.