Abstract: A high hardness sleeve or surface treatment to a predetermined hardness is used in a packing bore for a fluid end of a pump assembly. The bore is either treated to provide the hardness or a sleeve is used which is fitted in an oversized bore for preventing washout failure. The sleeve is welded into the pump block and machined to the proper size bore. Thereafter the bore is protected from washout failure at this location. Alternatively, a surface of the sleeve is polished which further reduces the wear on the part. The sleeve can be a stainless steel material hardened by heat treating process or otherwise treated or carbon steel sleeves with the predetermined bore hardness which could be welded into a suitable bore in the pump. However, other processes for hardening the stainless steel can be used as long as desired predetermined surface hardness is maintainable.