Dorman H621978 Brake Hydraulic Hose - Rear Left

Reliable Brake Hydraulic Hose for Infiniti FX50, G37, and QX70

The Dorman H621978 brake hydraulic hose is designed to provide dependable brake fluid transfer for select Infiniti models. Engineered with durable materials, this flexible hose ensures consistent braking performance for your Infiniti FX50, G37, and QX70 vehicles.

• Compatible with Infiniti FX50, G37, and QX70 models
• Flexible brake hydraulic hose constructed from EPDM rubber
• Black outer sleeve made of durable rubber for protection
• Ends feature treated steel fittings: junction type (End 1) and female type (End 2)
• Overall length of 13.54 inches for precise fitment
• Includes one brake hose; mounting hardware and brackets not included

Durable Construction and Precise Fitment

This Dorman brake hydraulic hose (part number H621978) is built with an EPDM rubber hose material that resists heat, ozone, and brake fluid degradation. The black rubber outer sleeve adds an extra layer of protection against abrasion and environmental factors. Both ends of the hose feature treated steel fittings—End 1 is a junction fitting with an M11 x 1.0 thread diameter, while End 2 is a female fitting with an M10 x 1.0 inside diameter—ensuring secure and leak-free connections within the brake system. With an overall length of 13.54 inches, this hose is designed to match the original equipment specifications for Infiniti FX50, G37, and QX70 models.

Common Applications and Problem Resolution

• Replaces worn or cracked brake hydraulic hoses causing fluid leaks
• Restores proper brake fluid flow for consistent braking response
• Addresses hose swelling or bulging under pressure
• Eliminates brake pedal softness due to hose failure
• Prevents contamination and brake fluid loss from damaged fittings

Installation Notes and Tips

Installation of the Dorman H621978 brake hydraulic hose requires basic mechanical skills and proper brake system knowledge. Before installation, ensure the vehicle is securely lifted and supported. Carefully remove the old hose, avoiding contamination of the brake fluid system. Use appropriate tools to disconnect the treated steel fittings, noting the thread sizes (M11 x 1.0 for End 1 and M10 x 1.0 for End 2). After installing the new hose, bleed the brake system thoroughly to remove air and verify leak-free connections. This hose does not include mounting hardware or brackets, so reuse existing components or source replacements as needed.

Quality Assurance and Warranty

Dorman manufactures the H621978 brake hydraulic hose to meet or exceed OEM standards for durability and performance. The use of EPDM rubber and treated steel fittings ensures resistance to corrosion and brake fluid exposure. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Refer to Dorman’s official documentation for complete warranty information.