TRW PMK479 Brake Master Cylinder

Brake Master Cylinder for Mercedes-Benz Applications

Restore consistent brake pedal response with this TRW brake master cylinder, part number PMK479. It is built with an aluminum body, a 19.05 mm bore, and a straight bore design for direct hydraulic performance on select Mercedes-Benz models.

Compatible With 1998-2002 Mercedes-Benz C230, C280, CLK320, and SLK230 applications, this TRW PMK479 master cylinder is a practical replacement for worn or leaking brake hydraulics. It also cross-references Monroe Shocks & Struts (e.g., 54307701) for the same application.

Key Features

• TRW brake master cylinder, part number PMK479
• Aluminum master cylinder construction
• 19.05 mm primary bore diameter with straight bore type
• Two piston design with three ports
• Dust boot included
• Gasket or seal included
• Primary and secondary outlet thread size: M12 x 1.0
• Mounting hole quantity: 2 with 8.8 mm mounting hole diameter
• No reservoir, cap, booster, push rod, or mounting hardware included

Detailed Description

The TRW PMK479 brake master cylinder is engineered for hydraulic brake systems that require stable pressure transfer and reliable pedal feel. Its aluminum housing helps keep weight down while maintaining the structural support needed for everyday braking performance. The 19.05 mm bore diameter, straight bore layout, and dual-piston design support consistent fluid movement through the brake circuit.

This master cylinder is listed for 1998-1999 Mercedes-Benz C230, 1998-2000 Mercedes-Benz C280, 1998-1999 Mercedes-Benz CLK320, 1999-2000 Mercedes-Benz SLK230, and 2002 Mercedes-Benz CLK320. If you are replacing a leaking or internally bypassing unit on a Mercedes-Benz C280 or CLK320, PMK479 provides the core hydraulic component needed to restore brake system operation.

What This Part Helps Address

• Low or sinking brake pedal feel
• Brake fluid leakage at the master cylinder body or outlets
• Internal bypass that reduces hydraulic pressure
• Uneven or inconsistent brake response
• Brake warning concerns related to master cylinder wear

Installation Notes and Tips

Before installation, verify outlet thread size, mounting hole spacing, and bore specifications against the original unit. This master cylinder does not include a reservoir, cap, booster, push rod, bleeder screws, or mounting hardware, so reuse or source the required related components as needed. Bench bleeding is recommended before final installation to help remove trapped air from the hydraulic passages.

For best results, inspect brake lines, seals, and the brake booster condition during replacement. Confirm fitment for your specific Mercedes-Benz C230, C280, CLK320, or SLK230 by matching the original part number and hydraulic connections.

Quality Assurance

TRW is a recognized brake component manufacturer, and PMK479 is built to meet the dimensional and functional requirements of the listed Mercedes-Benz applications. Use the confirmed fitment data and OE-style specifications to verify application before installation.