New Brake Master Cylinder 1-1/8-inch bore size 29789 3769225 75
Bexar Pro Components: Heavy-Duty Reliability for Fleet & Industry.
Key Specifications & Expert Features
- Bore Diameter: 1-1/8-inch bore size (Essential for heavy-duty pressure requirements)
- Outlet Size: 7/16-24 INV (Standard thread for direct line connection)
- Application: Medium-to-heavy duty fleet and industrial hydraulic systems.
- Companion Repair Kit: 253MK (View Compatible Kit)
Verified Casting & Part Numbers
Matching your existing part number is the most reliable method to ensure correct fitment. This unit replaces:
- 29789
- 3769225
- 75
- 29789C
- 616629
- 616634
Expert Installation & Field Note
Based on our shop experience specializing in heavy-duty brakes since 1985: The 1-1/8-inch bore size is a precision specification for specific hydraulic displacements. When installing the M3440374, verify your pushrod alignment to ensure the internal piston travels squarely within the bore. Side-loading or improper stroke adjustment is the primary cause of internal seal bypass in industrial applications. Always perform a full system flush with fresh fluid following installation.
⚠ CRITICAL: Verify Specifications
To ensure safety, verify that this master cylinder’s 1-1/8-inch bore size and 7/16-24 INV outlet match your existing unit exactly before purchasing.












