TRW PML447 Brake Master Cylinder

Brake Master Cylinder for Mercedes-Benz Applications

TRW PML447 is a brake master cylinder built for select Mercedes-Benz models with the specified 25.4 mm piston application. It uses an aluminum body, a straight bore design, and dual piston construction to support consistent hydraulic brake pressure in the master cylinder assembly.

Compatible With Mercedes-Benz SLK300, SLK350, SLK55 AMG, CLK350, CLK550, CLK63 AMG, SLK280, C230, C280, C350, C55 AMG, CLK500, CLK55 AMG, C240, C320, CLK320, and C32 AMG applications listed below. This part cross-references 54309801 for the same application.

Key Features

• TRW brake master cylinder, part number PML447
• Aluminum master cylinder housing for brake hydraulic service
• Straight bore type with 20.64 mm primary bore diameter and 25.4 mm secondary bore diameter
• Two piston design with three ports and M12 x 1.0 primary and secondary outlet threads
• Dust boot included
• Gasket or seal included
• No reservoir, cap, push rod, brake booster, or mounting hardware included

Detailed Description

TRW PML447 is a brake master cylinder for Mercedes-Benz brake hydraulic systems that require the listed 25.4 mm piston configuration and ATE original part vendor specification. The aluminum construction supports a direct replacement approach for vehicles such as the Mercedes-Benz C320, CLK500, SLK350, and C55 AMG, while the straight bore layout and dual piston design help maintain proper brake fluid pressure transfer through the master cylinder. The unit includes a dust boot and seal, and it uses M12 x 1.0 outlet threads with three ports for the specified brake plumbing layout.

Fits 2009-2011 Mercedes-Benz SLK300, N/A; Fits 2005-2011 Mercedes-Benz SLK350, N/A; Fits 2005-2010 Mercedes-Benz SLK55 AMG, N/A; Fits 2006-2009 Mercedes-Benz CLK350, N/A; Fits 2007-2009 Mercedes-Benz CLK550, N/A; Fits 2007-2008 Mercedes-Benz CLK63 AMG, N/A; Fits 2006-2008 Mercedes-Benz SLK280, N/A; Fits 2006-2007 Mercedes-Benz C230, N/A; Fits 2006-2007 Mercedes-Benz C280, N/A; Fits 2006-2007 Mercedes-Benz C350, N/A; Fits 2005-2006 Mercedes-Benz C55 AMG, N/A; Fits 2003-2006 Mercedes-Benz CLK500, N/A; Fits 2003-2006 Mercedes-Benz CLK55 AMG, N/A; Fits 2003-2005 Mercedes-Benz C240, N/A; Fits 2001-2005 Mercedes-Benz C320, N/A; Fits 2003-2005 Mercedes-Benz CLK320, N/A; Fits 2002-2004 Mercedes-Benz C32 AMG, N/A.

What This Part Helps Address

• Brake pedal travel that feels excessive or inconsistent
• Loss of hydraulic pressure in the brake system
• Internal master cylinder leakage
• Brake fluid seepage around the master cylinder area
• Restoration of proper brake pedal response after master cylinder wear

Installation Notes and Tips

Verify the bore size, outlet thread size, port count, and vehicle brake configuration before installation. This master cylinder does not include a reservoir, cap, push rod, brake booster, or mounting hardware, so reuse or source the required related components as needed. Bench bleeding is recommended before final installation to reduce trapped air in the hydraulic circuit and help restore a firm pedal.

Quality Assurance

TRW is a recognized brake component manufacturer, and PML447 is built to match the listed Mercedes-Benz applications and interchange reference. Confirm fitment against the vehicle’s original master cylinder specifications before installation.