York International 665-25186-000 Unloader Piston

The York 665-25186-000 Unloader Piston is a precision-machined, high-strength industrial alloy component used in HVAC compressor systems to regulate capacity by loading and unloading compressor cylinders. It is designed for installation in York chillers and compressor units to support capacity control in industrial HVAC and refrigeration applications, including chillers, compressor assemblies, and process cooling systems in commercial buildings and industrial facilities. Constructed for internal compressor assembly use in high-pressure refrigeration environments, this piston is intended for replacement and system servicing, with common replacements including York 665-25185-000, York 665-25187-000, and York 665-25150-000.