TRW PML172 Brake Master Cylinder

TRW PML172 Brake Master Cylinder

The TRW PML172 brake master cylinder is a direct-fit hydraulic replacement for select Audi and Volkswagen models with a 25.4 mm straight bore and dual M12 x 1.0 outlet threads. Built from aluminum with two mounting holes, it includes a dust boot and gasket/seal for service-ready installation on the listed applications.

Key Features

• Brake master cylinder for brake hydraulic service
• 25.4 mm primary bore diameter with straight bore type
• Aluminum master cylinder body
• Two port design with primary and secondary outlet thread size M12 x 1.0
• Dust boot included
• Gasket or seal included
• Two mounting holes with 22 mm mounting hole diameter
• No reservoir, cap, push rod, brake booster, or mounting hardware included

Fitment Details

• Fits 2001-2003 Audi A8 Quattro, N/A, without electronic stability control.
• Fits 2001-2003 Audi S8, N/A, without electronic stability control.
• Fits 2002 Audi S4, N/A, without electronic stability control.
• Fits 2000-2001 Audi A4, N/A.
• Fits 2000-2001 Audi A4 Quattro, N/A.
• Fits 2000-2001 Audi A6, N/A.
• Fits 2000-2001 Audi A6 Quattro, N/A.
• Fits 2000-2001 Audi S4, N/A.
• Fits 2001 Volkswagen Passat, N/A, without electronic stability control.
• Fits 2000 Volkswagen Passat, N/A.
• Fits 1999 Audi A4 Quattro, N/A, from chassis/VIN 8D-X-200 001.
• Fits 1997-1999 Audi A8, N/A.
• Fits 1997-1999 Audi A8 Quattro, N/A.
• Fits 1999 Volkswagen Passat, N/A, from chassis/VIN 3B-X-491 581.

What This Part Helps Address

• Low or inconsistent brake pedal response
• Internal hydraulic leakage in the master cylinder
• Brake fluid loss at the cylinder body or outlet ports
• Pedal travel issues caused by worn hydraulic seals
• Brake system performance concerns on Audi A4, A6, A8, S4, S8, and Volkswagen Passat applications

Installation Notes

Verify the vehicle’s brake system configuration before installation, especially electronic stability control coverage and VIN breakpoints listed in the fitment data. Confirm the 25.4 mm bore, M12 x 1.0 outlet threads, and two-hole mounting pattern match the original unit on your Audi or Volkswagen. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

Quality Assurance

TRW brake hydraulics are built for OE-style service replacement, with aluminum construction and included sealing components to support proper hydraulic function on the specified vehicles. The TRW PML172 is identified for use on 1997-2003 Audi and 2000-2001 Volkswagen Passat applications listed above.