TRW PMK321 Brake Master Cylinder

Brand TRW PMK321
Reservoir Material None
Dust Boot Included Yes
Mounting Hardware Included No
Gasket Or Seal Included Yes
Mounting Hole Quantity 2
Master Cylinder Bore Diameter 19.05
Bleeder Screw Included No
Piston Quantity 2
Brake Booster Included No
Master Cylinder Material Aluminum
Push Rod Included No
Reservoir Included No
Bleeder Hoses Included No
Sensor Included No
Port Quantity 2
Mounting Bracket Included No
Bore Type Straight
Primary Outlet Thread Size M12 - 1.0
Brake Pressure Switch Required No
Brake Pressure Switch(s) Included No
Primary Bore Diameter 19.05
Fits Mercedes-Benz · 12 vehicles

Aluminum construction. Lightweight master cylinder body for dependable hydraulic performance.

Seal included. Helps simplify installation with a gasket or seal provided.

Straight bore design. Supports consistent brake fluid flow through the master cylinder.

Cross-references 54306401 and 005430640164 for the same application. See all 2.

$168.67Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
Free return shipping if it doesn't fit when you check fitment here first.
Select your vehicle to confirm fitment
Verify this part fits before purchasing — free returns if it doesn't
Step 2 — Quantity
Order total $168.67
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.

Brake Master Cylinder for Mercedes-Benz Applications

The TRW PMK321 brake master cylinder is a direct-fit hydraulic replacement for select Mercedes-Benz models, including the C230, C280, C36 AMG, C220, and SLK230. Built with an aluminum body and a 19.05 mm bore, it is specified for vehicles that need a straight-bore master cylinder with two mounting holes and two outlet ports.

  • TRW brake master cylinder, part number PMK321
  • Aluminum master cylinder construction
  • 19.05 mm bore diameter with straight bore type
  • Two mounting holes and two port connections
  • Dust boot included
  • Gasket or seal included
  • No reservoir included
  • No brake booster, push rod, sensor, or mounting hardware included
  • Primary outlet thread size: M12 x 1.0

Fitment Details

  • Fits 1998 Mercedes-Benz SLK230, N/A
  • Fits 1997 Mercedes-Benz C230, N/A
  • Fits 1994-1997 Mercedes-Benz C280, N/A
  • Fits 1995-1997 Mercedes-Benz C36 AMG, N/A
  • Fits 1994-1996 Mercedes-Benz C220, N/A

Detailed Description

TRW PMK321 is a brake master cylinder engineered for hydraulic brake systems that require a 19.05 mm primary bore and two-port layout. The aluminum housing helps keep the assembly lightweight while maintaining the dimensional accuracy needed for proper brake pedal response and fluid pressure delivery. This part cross-references OE-style applications for Mercedes-Benz brake system service, including 54306401 and 005430640164.

Use PMK321 when servicing a Mercedes-Benz C230, C280, C36 AMG, C220, or SLK230 that calls for this master cylinder configuration. The unit includes a dust boot and seal, while the reservoir, brake booster, push rod, sensor, and mounting hardware are not included.

Common Brake System Issues It Can Address

  • Low or inconsistent brake pedal feel caused by internal master cylinder wear
  • Brake fluid bypass from worn piston seals
  • External leakage at the master cylinder body or outlet area
  • Uneven hydraulic pressure delivery to the brake circuits
  • Brake warning symptoms tied to master cylinder deterioration

Installation Notes and Tips

Confirm bore diameter, outlet thread size, port count, and reservoir style before installation. Bench bleed the master cylinder before connecting brake lines, then bleed the full hydraulic system after installation to remove trapped air. Inspect the brake booster interface, line fittings, and mounting surfaces for wear or contamination before assembly.

Quality Assurance

TRW is a recognized brake component manufacturer with OE-level application coverage in hydraulic braking systems. PMK321 is built to match the specified Mercedes-Benz fitment and hydraulic configuration for the listed vehicles.

This part fits 12 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelBody Type# DoorsLitersCylindersFuel TypePositionNotes
1998Mercedes-BenzSLK230KompressorConvertible2 Door2.3LL4GASN/A
1997Mercedes-BenzC230ClassicSedan4 Door2.3LL4N/A
1997Mercedes-BenzC280BaseSedan4 Door2.8LL6N/A
1997Mercedes-BenzC36 AMGBaseSedan4 Door3.6LL6N/A
1996Mercedes-BenzC220BaseSedan4 Door2.2LL4N/A
1996Mercedes-BenzC280BaseSedan4 Door2.8LL6N/A
1996Mercedes-BenzC36 AMGBaseSedan4 Door3.6LL6N/A
1995Mercedes-BenzC220BaseSedan4 Door2.2LL4N/A
1995Mercedes-BenzC280BaseSedan4 Door2.8LL6N/A
1995Mercedes-BenzC36 AMGBaseSedan4 Door3.6LL6N/A
1994Mercedes-BenzC220BaseSedan4 Door2.2LL4N/A
1994Mercedes-BenzC280BaseSedan4 Door2.8LL6N/A
Directly replaces or cross-references 2 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
54306401005430640164