The probable causes include an obstruction that is slowing the water flow, the pump and/or unloader needs cleaning, or the engine (gas model) needs adjustment.
Tools that may be needed: channel-lock pliers.
First, check for any clogs in the system. Then, clean the unit. Lastly, if a gas model, the engine may need serviced.
Purging system of clogs or obstructions:
- Turn off the pressure washer and water and squeeze the spray gun trigger to relieve pressure in the system.
- Disconnect the garden hose from the pump and turn the water on to be sure that the pressure is adequate (30 psi minimum). If pressure is good, check the pump’s inlet connection for any clogs and reconnect the hose. Make sure there are no kinks in the hose.
- Disconnect the pressure hose from the pump outlet.
- Place the pressure washer in a position that has the pump outlet facing an open area.
- Turn on the water and then start the pressure washer. If the pump is free of any obstructions, the water will shoot 15-20 feet out of the pump outlet. If there is little or sporadic flow of water, the problem is in the pump. It may simply need cleaning.
Cleaning and lubricating the pump:
- Reconnect the high-pressure hose and squeeze the trigger to relieve any pressure.
- Disconnect the garden hose from the pump.
- Using a funnel or short length of garden hose, pour 2 cups of vinegar into the inlet side of the pump. Squeeze the gun trigger and briefly turn on the unit to engage the pump only long enough for all the vinegar to circulate through the pump. Do not leave the pressure washer running. This is meant to clean the pump and free any internal components that are stuck.
- Unplug the unit. Let the vinegar set inside the pump 3-4 hours then flush it out with water.
- Again, using a funnel or short length of garden hose, pour 2 cups of vegetable oil into the inlet side of the pump. Repeat Step 3, using the oil in place of the vinegar. This will lubricate and protect the internal components.
- Unplug the unit. Let the oil set inside the pump 3-4 hours, then flush it out with water.
- With the garden hose turned on and reconnected to the pump, squeeze the gun trigger and start the unit.
- If the unit still surges, this indicates a more serious condition in the pump or the motor/engine. If your unit is under warranty, take it into the nearest service center for repair. If it is not under warranty, you should take it into the nearest service center or call Campbell Hausfeld Technical Support at (800) 543-6400.
- If it can be determined that the issue is associated with the engine, please refer to your engine manufacturer's manual or web site. Or contact a local service center or small engine repair shop.