Simpson OEM Technologies 90026 Axial Cam Pump 3100PSI 2.4GPM Replaces 510020 by | Jul 22, 2026Sold individually. Pump Type:Vertical Axial Cam. Replaces:510020, 51AL24. Features:Maintenance-free crankcase — never change pump oil. Thermal relief protection. Stainless steel pistons for extended seal life.