Back-up O-ring for Terex PT50

The back-up O-ring 0403-002 serves as a support component for the relief valve assembly located within the drive and auxiliary pump system of the Terex PT50. This part is engineered to provide mechanical reinforcement to the primary O-ring seal, preventing it from extruding or deforming when subjected to the high-pressure conditions typical of hydraulic circuits. By maintaining the position and structural integrity of the primary seal, it ensures the relief valve functions as intended to manage system pressure.

This component is specifically configured for use in the Terex PT50 compact loader. It functions as a critical interface within the relief valve mechanism, which is responsible for protecting the hydraulic pump and associated circuitry from overpressure events. The actual manufacturer for this component is Terex.

In hydraulic systems, back-up rings are used in conjunction with O-rings in high-pressure applications. They prevent the primary seal from being forced into the clearance gap between mating parts, which would otherwise lead to seal failure and subsequent fluid leakage. Proper installation of this back-up ring is necessary for the relief valve to maintain accurate pressure settings and prevent damage to the broader hydraulic architecture of the machine.