New Brake Master Cylinder 3/4-inch bore size 29891-C 5470819 5470876
Bexar Pro Components: Heavy-Duty Reliability for Fleet & Industry.
Key Specifications & Expert Features
- Bore Diameter: 3/4-inch bore size (Critical for correct power-assist pedal ratios)
- Outlet Sizes: 9/16″-18 & 1/2″-20 INV (Standard dual-line configuration)
- Components: Unit includes a new pushrod for simplified installation.
- Application: Optimized for power brake systems in classic trucks and light commercial fleets.
- Repair Kit: N/A (Complete unit replacement recommended for power-assist safety)
Verified Casting & Part Numbers
Matching your existing casting number is the most reliable method to ensure correct fitment. This unit replaces:
- 29891-C
- 5470819
- 5470876
- 5470878
- C5470878
- C5470876
Expert Installation & Field Note
Based on our shop experience specializing in heavy-duty brakes since 1985: The smaller 3/4-inch bore size is specifically engineered to work with the low-pressure input from a brake booster, providing a firm, responsive pedal feel. When installing the M7616652, verify your pushrod alignment to ensure the internal piston travels squarely within the bore. Using this master cylinder in a manual (non-power) brake system will result in excessive pedal travel and unsafe performance.
⚠ CRITICAL: Verify Specifications
To ensure safety, verify that this master cylinder is for Power Brake Applications ONLY. Physically verify that the 3/4-inch bore size and outlet threads match your existing unit exactly before purchasing.















