CAT 078-7431 ARBRE DE FRE

CAT 078-7431
ARBRE DE FRE Brake Shaft
Basic Information
Part Number: CAT 078-7431
Name: ARBRE DE FRE (French, equivalent to Brake Shaft), i.e., brake shaft
Application: Used inside the brake assembly to transmit braking torque, connect the brake shoes/pains to the actuator, and ensure synchronized and smooth braking action.

Core Parameters (Original Equipment Manufacturer Specifications)

Material: 42CrMo alloy steel, tempered + surface hardened

Hardness: HRC 45–52

Structure: Stepped shaft, with spline/keyway, bearing seat, oil seal seat

Applicable Systems: Brake assembly, parking brake/service brake mechanism

Compatible Models: 306E/307E excavators, 226B3/236B3/246B3 skid steer loaders, 3044C/3054C engine matching braking system

Function and Assembly Location
Installed inside the brake housing, serving as the core shaft for brake actuation
One end connects to the brake rocker arm/fork, the other end connects to the brake shoe/brake drum
Bears braking torque and radial load, ensuring consistent braking response and no jamming

Belongs to the same braking system components as 078-7406 brake seat ring and 078-7430 sealing gasket assembly

Installation and Maintenance Points
Junior journal, keyway/ Splines must be clean, free of burrs and rust. Apply special grease to bearing seats and oil seals to prevent dry friction and scoring. After assembly, check for axial runout ≤0.05 mm, and ensure smooth rotation without jamming or abnormal noise. Check journal and spline wear every 500 hours; replace immediately if wear exceeds tolerance. Replace parts simultaneously with gaskets, oil seals, and seat rings to prevent leaks/loosening caused by old components.