If the crankcase of your pump has cracked or something is causing it to malfunction and you can't figure out the cause, this rear assembly is just what you need. The CAT Pumps 340RA-WP is a complete rear assembly for their model 340 pumps. This assembly includes everything inside the crankcase and the plungers, but not the manifold head components. Each part included in this assembly is a genuine OEM component from CAT Pumps.