greenworks pressure washer leaking water from the pump area when i turn it off, is that normal?

Diagnosis

The Greenworks GPW1804 utilizes an axial cam pump design. When you switch the unit off, the water remaining in the pump head and the high-pressure hose remains under significant tension. Because this model lacks an automatic pressure relief valve (unloader) that vents back to the intake, the trapped pressure pushes against the internal O-rings and piston seals. If you see a slow drip from the pump housing immediately after shutdown, it is usually "pressure bleed," where water is forced past the seals because the system hasn't been depressurized. However, if water is actively streaming from the pump casing or pooling at the base of the motor assembly, you likely have a failure in the pump's manifold seal or a loose fitting at the water inlet. To confirm, wipe the pump dry with a microfiber cloth, turn the unit on for 60 seconds, and then turn it off. If the water appears specifically around the pump head gaskets or the pump-to-motor interface, the seals are compromised. If it only drips for 10-20 seconds and then stops, it is a symptom of residual pressure trapped in the line.

How to Fix It

To stop the leaking and protect your pump seals from premature wear, you must implement a strict depressurization sequence. Follow these exact steps:

1. Switch the power button to the "OFF" position. Do not unplug the unit yet.
2. While the motor is off, squeeze and hold the trigger on the spray wand. Keep the wand pointed at the ground or into a bucket.
3. Continue holding the trigger until the water flow stops completely. This releases the trapped pressure from the hose and the pump manifold.
4. Only after the pressure is released should you turn off the water supply faucet.
5. Disconnect the garden hose from the pump inlet and let any remaining water drain out of the pump head to prevent internal corrosion or freeze-cracking.
6. Check the O-ring inside the garden hose connector (the female end of the hose attaching to the GPW1804). If it is flattened or cracked, replace it with a 1/2-inch standard rubber washer to ensure a watertight seal at the intake.

If That Didn't Work

• Inspect the Pump Manifold Bolts: Over time, the vibration of the 1800 PSI motor can loosen the bolts securing the pump head to the motor. Use a metric socket set to ensure the bolts on the pump housing are snug, but do not over-tighten them, as the aluminum housing can crack easily.
• Replace the High-Pressure Hose Gasket: If the leak appears to be coming from the pump but is actually spraying upward from the hose connection, the internal O-ring in the high-pressure hose fitting has failed. Unscrew the hose, remove the damaged rubber ring, and install a replacement high-pressure seal.
• Check for Air Leaks (Cavitation): If the pump is "shuddering" before it leaks, you may have air in the line. Ensure your garden hose is fully seated and the faucet is open 100%. If the pump sucks air, it creates vacuum bubbles that can force water out of the seals during the shutdown phase.
• Pump Replacement: If the leak is originating from the center of the pump casting (the pump body itself), the internal piston seals have blown. Because the GPW1804 pump is a sealed unit, it cannot be rebuilt. You will need to replace the entire pump assembly.

Heads Up

• Never run the pump dry: Running the unit for even 30 seconds without water will overheat the seals and cause immediate, permanent leaking.
• Winterization is critical: If you live in a freezing climate, any water left in the pump head will expand and crack the manifold. Always use a pump protector or store the unit in a heated garage above 40°F.
• Avoid "Trigger-Locking": Do not use clamps or tape to keep the trigger open. This puts unnecessary strain on the motor and can lead to pump overheating.
• Use a 5-Gallon Pre-Filter: To prevent grit from scoring the internal seals and causing leaks, attach a sediment filter to your garden hose before it enters the pump.