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520002 OEM Technologies Axial Cam 3/4″ Shaft Pump 3400 PSI 2.5 GPM
| Part Number | 520002 |
| Brand | OEM Technologies |
| Item Weight | 6 lbs |
| Mounting Orientation | Horizontal |
| Part Type | Pressure Washer Pump |
| Max Pressure | 3400 |
| Flow Rate | 2.5 |
| Inlet Size | 3/4” Garden Hose |
| Outlet Size | M22 |
| Shaft Size | 3/4" |
| Bolt Pattern | SAE J-609A |
| Drive Key Size | 1" x 3/16" |
| Oil Capacity | 6.0 fl oz. |
The 520002 is a horizontally mounted axial cam pump rated at 3,400 PSI and 2.5 GPM, designed as a direct OEM replacement for Simpson, DeWalt, Craftsman, Cub Cadet, and other gas pressure washers running a 3/4" horizontal shaft engine. It features a black-anodized die-cast aluminum crankcase with a brass head, comes pre-filled with 6 oz. of 15W40 synthetic oil, and is equipped with PowerBoost Technology paired with a stainless steel integrated unloader for maximum pressure output and easy starts.
- 3,400 PSI / 2.5 GPM - horizontally mounted axial cam with 3/4" shaft
- PowerBoost Technology - stainless steel unloader with easy-start system delivers higher pressure at the nozzle
- Black-anodized brass head construction - pre-filled with synthetic oil, maintenance-free crankcase, thermal relief valve included for overheat protection
Part numbers 4200002, 8.6CAH12, 90029 are other numbers used for the same product as 520002. These are alternative part numbers used to identify this product.
| Alternate Part # | Equivalent To | Status |
|---|---|---|
| 4200002 | = 520002 | Same Product |
| 8.6CAH12 | = 520002 | Same Product |
| 90029 | = 520002 | Same Product |
This part is designed to work with the engine models listed above. Engine compatibility is based on shaft size, bolt pattern, and mounting orientation.
Low or no pressure typically traces back to two places: the unloader valve or the check valves. When a pump sits with water inside, mineral deposits and corrosion can prevent the check balls from seating properly, causing water to recirculate internally rather than building pressure at the nozzle. A cracked piston or clogged inlet screen produces the same symptom by restricting water flow before it reaches the pumping chamber.
Remove and inspect the unloader assembly. Clear and clean debris to ensure the unloader ball moves freely. If damage is present, the unloader may need to be replaced. Another possibility is the pressure valves inside of the manifold, inspect and/or replace if damage present.
The pump relies on a set of seals to keep water contained inside the manifold under pressure. Normal wear, heat cycling, or running the pump without water flow degrades these seals over time. Once they fail, water bypasses the pistons and leaks out through the weep holes located between the crankcase and pump head.
Remove the manifold and inspect the pressure seals and O-rings. If replacing, using kit part number 7106627 to replace the worn or damaged seals.
Rapid pulsation or a thumping sensation in the hose usually points to a stuck check valve. The pump uses six check valves (three on the inlet side, three on the discharge side) to control water flow direction. If debris lodges inside one of these valves and prevents it from closing fully, water backflows on every piston stroke, creating erratic pressure spikes and thumping or chattering.
Turn off the engine, water, and remove the discharge hose. Turn on your water supply and let the water purge any trapped air inside of the pump. If the issue persists, remove the manifold and inspect the valves. Clean out debris or replace if damaged.