SIMPSON Pressure Washer Manifold Replacement Kit for OEM 510020/520006 - Complete Valve, Unloader & TRV Repair Kit

If your gas pressure washer is losing pressure, leaking, or delivering poor detergent flow, this manifold replacement kit provides the critical parts to rebuild the pump manifold quickly. The kit contains valves, seals, an unloader, thermal relief valve (TRV), integrated soap injector, a 3/4" garden-hose low-pressure inlet, an M22 high-pressure outlet and all mounting hardware engineered to match OEM fit and function.

How will this kit fix low pressure or leaks?

The manifold kit replaces worn seals, valves and fittings that commonly cause pressure loss and leaks in axial cam pumps. Installing the new components restores proper fluid pathways and valve seating so the pump can re-establish rated output.

• Complete valve and seal set to stop internal bypass and external leaks
• New unloader reduces excess pressure and prevents pump overload
• Thermal relief valve protects the pump from heat-related damage
• Direct-fit parts for OEM 510020 and 520006 models minimize modification

What parts are included and why they matter?

This kit bundles every component required to replace the manifold assembly so you won’t need separate parts orders. Each included item addresses a specific failure point—valves control flow, seals prevent leakage, and the unloader & TRV manage pressure and temperature for safe operation.

• Valves and seals: restore proper pressure and sealing surfaces
• Unloader: routes water to bypass when gun is closed, protecting the pump
• TRV: relieves trapped heat to avoid seal and component damage
• Integrated soap injector and fittings: enable detergent application and easy hose connections

How long does installation take and what tools are needed?

Installation time varies with experience but most technicians or competent DIYers can complete the manifold swap in one to two hours. The kit arrives with the necessary hardware; you’ll need common hand tools, a torque wrench for correct fastener tension, and basic mechanical skills.

• Expected install time: about 60–120 minutes for an experienced user
• Tools: standard sockets/wrenches, torque wrench, screwdrivers, pliers
• Pre-install prep: drain pump, clean mounting surface, inspect housing for wear
• Follow OEM torque and assembly sequence to ensure reliable sealing

Will this kit work with my pressure washer?

Compatibility is limited to OEM Technologies axial cam pump models 510020 and 520006; confirm the pump model stamped on your unit before ordering. The kit is designed as a direct replacement for those specific manifolds and fittings, avoiding fitment issues common with universal parts.

• Compatible models: OEM Technologies 510020 and 520006
• Includes 3/4" garden-hose low-pressure inlet and M22 high-pressure outlet
• Designed for gas axial cam pumps used in residential and light commercial applications
• Not a universal manifold—verify pump model for correct fit

Who is this for: The Simpson Cleaning Manifold Replacement Kit is ideal for homeowners, landscapers, contractors and service technicians who need a reliable, OEM-grade repair to restore pressure washer performance. Choose this kit when your axial cam pump shows signs of leaking, poor pressure, or soap-feed problems and you prefer genuine Simpson/OEM-compatible components for longevity and correct operation.