This brake pump repair kit contains the seals, gaskets, and internal components needed to restore the hydraulic actuation assembly of the host tractor's braking system. It sits within the pump housing, where its seals maintain pressure between the piston and bore. A leaking or worn seal set causes a soft pedal and reduced braking force, as fluid bypasses the piston rather than being directed to the wheel cylinders. The manufacturer machines the elastomers to the same cross-section and durometer as the original assembly, so the piston stroke and cracking pressure match the factory specification. On installation, clean the bore thoroughly and lubricate the new seals with clean brake fluid before assembly.