If you are purchasing your own high pressure pump, you should purchase from a reputable, OE manufacturer. The quality of any remanufactured high pressure pump depends on the remanufacturing process and components.
Remanufactured does not mean “used” or “rebuilt”. It means that the part has been manufactured again. 100% of all parts are examined and the non-wearable parts are re-used. However, if there are any flaws, the part is discarded. The high pressure pump is rebuilt and all wearable components are replaced. The part is then tested before completion. The extent of the remanufacturing and testing process depends on the manufacturer.