Out of Stock: Clutch Brake Master Cylinder 1-1/8-inch bore size CM39325-A
Bexar Pro Components: Heavy-Duty Reliability for Fleet & Industry.
Superseded Part & Replacement Guide
To maintain your heavy-duty fleet reliability, you must transition to the standard base unit. The recommended replacement is currently in stock:
Key Specifications (Base Unit)
- Bore Diameter: 1-1/8-inch bore size (Essential for heavy-duty pressure calibration)
- Application: Chevy, Dodge, and Navistar medium-duty models.
- Critical Difference: The original “A” variant featured a longer integral pedal rod.
- Repair Kit: N/A (Complete unit replacement recommended)
Verified Casting & Part Numbers
Matching your existing casting number is the most reliable method to ensure the base unit fits. Replaces:
- 29962C
- FF42089
- 83230
- 5459951
- 618671
- B226
- FF51125
Expert Installation & Field Note
Based on our shop experience specializing in heavy-duty brakes since 1985: When installing the standard CM39325 replacement, you must reuse your original, longer pedal rod from the discontinued CM39325-A unit. Ensure the rod is not bent or pitted before swapping. Proper pushrod alignment is vital for pedal feel and to prevent internal seal damage. Always bench bleed the 1-1/8-inch bore unit and flush the hydraulic system with fresh fluid to protect the new cylinder’s honed surfaces.
⚠ CRITICAL: Action Required
Verify that your unit requires the 1-1/8-inch bore size. If your obsolete unit is an FF48468 (1.5″ Bore) or FF43812 (1.75″ Bore), please contact us for specific replacement alternatives. Correct bore size determines proper hydraulic displacement for automotive and industrial safety.


















