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Step by step guide

Go 10 year service

Servicing our pressure washers are quite straight forward and could be done by most people by following the step-by-step instructions in this manual.

Please go trough the whole manual before starting work on your pressure washer to make sure you understand the procedure and that you have the necessary tools to complete the task.

Always unplug the pressure washer from both the mains power and the water outlet before starting the service.

Even though power and water is disconnected there may be pressurized water in the hose. Discharge this pressure by pulling the trigger on the gun.

Make sure your work area is clean and appropriate for the work you are about to do. There will usually be a small amount of water inside the pump and hose.

If you are doing a 10-year service, then be prepared to collect the used oil from the oil chamber. Please dispose of the oil in accordance with local law and regulations.

ISO 46 hydraulic oil can be substituted with similar non detergent oil of the same viscosity.

00. Parts and tools

An overview of what is needed to do this service.

01. Remove water filter

Unscrew the water filter then remove it.

02. Remove screws from the front cover

Release the pressure hose from the pump outlet. Unscrew the four T25 screws from the front cover.

03. Remove screws from the tool holder

Turn the pressure washer upside down. Unscrew the two T25 screws from the tool holder.

04. Open the machine

Remove the bottom of the tool holder cover, then remove the front cover.

05. Remove on/off knob

Remove the on/off button and the power cable strain reliever.

06. Remove screws from the switch box

Unscrew the two T25 screws from securing the switch box and motor/pump assembly.

07. Remove the motor/pump assembly

Carefully lift out the motor/pump assembly.

Remove the motor cowling from the motor/pump assembly.

08. Remove u-pins

Remove the two U-pins securing the inlet and outlet pipes from the pump head. Use a small flat head screwdriver to pry them loose.

09. Remove inlet and outlet pipe

Remove the inlet and outlet pipes from the pump head.

Remove the switch box by pulling it in the direction indicated. It is press fitted onto the start/stop valve on the pump.

10. Remove screws from the pump head

Use a 5mm hex/Allen key to remove the three screws on the pump head.

11. Remove the pump assembly

Pull off the pump head, main valve and the pump housing.

Get a suitable container or bucket to catch the oil from the oil chamber. Unscrew the three 5mm Allen screws securing the piston house. Let the oil drain completely.

12. Remove piston house

Rotate the piston housing 15-20° counterclockwise.

Remove the piston kit assembly.

13. Clean and inspect the thrust bearing

If the oil drained from the oil chamber has a silver colour we recommend that you also take out the thrust bearing that rest on top of the wobble plate. Clean it and do a visual inspection for wear and damage. Damage to the balls and/or the upper or lower raceway requires the bearing to be changed. Clean the oil chamber using paper towels. Place the thrust bearing back onto the wobble plate.

14. Prepare a stable foundation for the motor

To fit the piston kit back onto the oil chamber requires a fair amount of force.

It is therefore recommended to use either a bench vise or create a platform on which the motor assembly can rest. If you are using a bench vise, it needs to be big enough so that you can get a firm grip on the stator core of the motor.

If no vise is available, then you can support the motor with wooden blocks or something similar to increase stability.

15. Refill oil

With the motor/pump well supported in the upright position, it is time to add some new oil to the oil chamber. Make sure to cover the top of the thrust bearing as indicated in the illustration below.

16. Prepare pump assembly

Lubricate the O-rings on the new parts as indicated.

17. Assemble the pump

Assemble the pump as shown. Take care to orient the pump head and the piston housing as indicated in the picture.

18. Fit the pump to the motor

Fit the preassembled pump to the oil chamber on the motor. A fair amount of force is needed to compress the piston springs so that the two mating surfaces meets. When the two mating surfaces touch, twist the pump assembly 15-20° clockwise so that the piston housing engages the lock tabs on the oil chamber.

19. Secure the pump assembly

Insert three short Allen screws to secure the pump assembly.

20. Attach the switch box

Attach the switch box to the pump. You may need to put decent amount of pressure to get the box firmly seated on the start/stop valve. It should pop into place.

Reattach the inlet and outlet pipes.

21. Secure inlet and outlet pipes

Secure the inlet and outlet pipes with two u-pins. You may want to use a small hammer or something similar to lightly tap them into the pump head.

22. Refit the motor cowling

Refit the motor cowling.

Turn the motor/pump unit so that the switch box and water inlet is facing up and place it back into the rear cabinet.

23. Secure the motor/pump assembly

Secure the motor/pump and the switch box using the two T25 screws.

24. Attach the on/off knob

Put the on/off knob back on to the switch box.

Fit the power cable strain reliever into the slot.

25. Fit the front cover

Fit the front cover.

Check that the on/off knob can rotate freely.

26. Secure the front cover

Fix the front cover to the back cover by using four T25 screws as indicated.

27. Secure the bottom tool holder cover

Fit bottom tool holder cover and secure it with two screws.

28. Attach water filter

Check that the filter cassette is clean, then refit the water filter.

29. First start after service

Congratulations with finishing the service of your AVA product.

It is now time to do the first start after service.

  1. Start by connecting the pressure gun to the hose.
  2. Connect water.
  3. Make sure no water is leaking from the inside or anywhere else on the pressure washer.
  4. Pull the trigger and let the water flow until there is no more air coming out.
  5. Connect the power cord.
  6. Turn on the pressure washer.
  7. Pull the trigger and let water run for a minute before connecting a nozzle.
  8. Connect the nozzle. Use the pressure washer and make sure it is operating as normal.

30. Troubleshooting

Water is leaking from the inside
  • Disconnect the power and open the pressure washer to locate the leak. Take necessary action to remedy any leaks.

Motor runs and won't stop when you release the trigger
  • This is most likely due to an improper seating of the switch box on the start/stop valve.
  • Open the machine and check that the switch box is correctly seated. The pressure washer won't turn on
  • Check that the power cable is connected.
  • Check that the circuit breaker has not been tripped.
  • Check that the fuse in the power plug is intact (UK models only).
  • Open the machine and check that all the internal cabling is connected.

Poor performance/pressure
  • Improper assembly or dirt/debris in the pump. Check that the pump and especially the main valve for foreign objects/debris. Make sure that the spring in the main valve is correctly seated and working as intended.