Drag Specialties Chrome Rear Master Cylinder Kelsey Hayes 3/4 Bore for 1979-1984 Harley-Davidson FL FX XL
Rebuilding a Shovelhead-era stopper back to its original stopping authority takes more than just parts — it takes the right part. This Drag Specialties reproduction delivers the hydraulic feel and lever response these machines left the factory with, giving riders back the braking confidence their build deserves without compromise.
Key Features
- Faithful reproduction of the original Kelsey Hayes master cylinder design for OEM-correct appearance and hydraulic feel
- Direct replacement for OEM part numbers 42453-80A and 42454-80A
- Arrives fully assembled and ready to install — no rebuild required
- Compatible with standard 1/8-27 NPT brake line fittings
- Correct 5/16″ mounting holes on 2.25″ centers match original factory mounting points
Technical Specifications
- Bore Size: 3/4″
- Inlet Size: 1/8-27 NPT
- Mounting Hole Diameter: 5/16″
- Mounting Hole Spacing: 2.25″ on center
- Length: 4″
- Width: 1.5″
- Height: 3.125″
- Construction: Chrome-plated cast aluminum
- OEM Cross-Reference: 42453-80A, 42454-80A
Fitment Notes
- All 1979 fitments apply to late production only; early 1979 models are not compatible
- 3/4″ bore is correct for stock single-piston calipers; use a 5/8″ bore unit with multi-piston aftermarket calipers
- Review the Fitment tab for the complete year and model breakdown
richard mutch –
perfect fit