Raybestos MC391152 Brake Master Cylinder

Raybestos MC391152 Brake Master Cylinder

The Raybestos Element3 New MC391152 brake master cylinder is built for select Lexus GS applications with a 0.750-inch bore, aluminum construction, and a 2-port layout. It is a direct-fit hydraulic replacement for drivers servicing brake pedal feel and master cylinder sealing concerns on compatible Lexus GS450h, GS460, GS300, and GS430 models.

Key Features

• Part number: MC391152
• Raybestos Element3; New product line
• Brake master cylinder for hydraulic brake systems
• Aluminum master cylinder body
• 0.750-inch bore size
• 2 mounting holes with 0.354-inch mounting hole diameter
• 2 ports with M10x1 primary and secondary port threads
• Cross-reference: Centric Parts 130.44042

Detailed Description

Raybestos MC391152 is a brake master cylinder engineered for select Lexus GS platform vehicles, including 2006 Lexus GS300, 2006 Lexus GS430, 2007-2011 Lexus GS450h, and 2010-2011 Lexus GS460. The aluminum housing helps keep the assembly lightweight while maintaining the dimensional accuracy needed for proper hydraulic connection and mounting. With a 0.750-inch bore and dual M10x1 ports, this master cylinder is specified for vehicles that require precise brake fluid transfer and consistent pedal response. The Raybestos Element3 line focuses on replacement brake components for everyday service work, and this MC391152 listing follows that OE-style fitment approach for Lexus GS brake hydraulics.

This part number, MC391152, is also referenced by other aftermarket listings for the same application, including Centric Parts 130.44042.

What It Is Used For

• Restoring brake pedal firmness when the master cylinder is worn internally
• Addressing external brake fluid seepage at the master cylinder body or ports
• Replacing a unit with damaged M10x1 port threads or mounting points
• Correcting inconsistent hydraulic pressure delivery in the brake system
• Servicing brake hydraulics on Lexus GS300, GS430, GS450h, and GS460 models

Installation Notes and Tips

Verify the bore size, port thread specification, and mounting hole layout before installation. This master cylinder uses 2 mounting holes, 2 ports, and M10x1 primary and secondary port threads, so brake line and mounting alignment should be checked against the original unit. After installation, the brake hydraulic system should be bled thoroughly to remove air and restore proper pedal feel. Confirm vehicle application by year and model before ordering; this part fits 2006 Lexus GS300, 2006 Lexus GS430, 2007-2011 Lexus GS450h, and 2010-2011 Lexus GS460.

Quality Assurance

Raybestos is a recognized brake parts brand, and the Element3 New line is positioned for replacement brake service with application-specific fitment. Part number MC391152 is cataloged for confirmed Lexus GS fitments and uses defined hydraulic and mounting specifications for accurate replacement selection.