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
Remove water filter by unscrewing it counterclockwise.
02. Remove the hose reel
Release the short pressure hose from the pump outlet. Unscrew the 3 T25 screws from the back cabinet. Take off the cover and the hose reel.
03. Remove screws from the back cabinet
Remove the power cable from the cable reel so you can access the two screws behind the reel. Unscrew the 11 T25 screws from the backside of the pressure washer.
04. Lift off the rear cabinet
Put the pressure washer face down. Lift off the rear cabinet. Release the strain reliever and the power cord.
05. Remove screws from the pump.
Unscrew the 3 T25 screws securing the motor/pump.
06. Remove the water outlet
Use a flat head screwdriver to pry loose the U-pin at the pump head. Remove the U-pin and then remove the high-pressure water outlet.
07. Remove the motor/pump
Carefully lift the motor/pump out of the front cover. Turn it 180° before placing it on a flat surface. Remove the on/off button, its extension and the pump head cover.
08. Disconnect the power cables
Release the motor power cables. The cables are connected with spade contacts. Push down the small locking tab (blue arrow) and gently pull the spade contacts apart.
09. Remove the ground cable
Unscrew the crosshead Phillips screw that secure the grounding cable to the motor.
10. Remove the switch box
Remove the switch box by pulling it in the direction indicated. It is press fitted onto the start/stop valve on the pump.
11. Loosen the screws securing the pump
Use a 6 mm hex/Allen key to loosen the 4 screws securing the pump assembly. Be ready to catch the oil from the oil chamber with a suitable container.
12. Remove the pump assembly
Rotate the whole pump assembly 15-20° counterclockwise to release it from the motor oil chamber.
13. Remove the pump assembly
Remove the complete pump assembly.
With the oil drained from the oil chamber, remove the top thrust bearing, the wobble plate and the bottom thrust bearing. On some older models the wobble plate is fixed to the motor axle with a hex bolt. If this is the case, get a firm grip on the motor fan to keep the axle still, while unscrewing this bolt. Remove the large oil chamber O-ring.
Clean the oil chamber using a rag or paper towel. Put in the new bottom thrust bearing, followed by the wobble plate and the top thrust bearing. If you removed a hex bolt from the axle, discard this as it is not needed.
14. Refill oil
Refill the oil chamber with ISO 46 hydraulic oil or another non detergent oil with the same viscosity.
The oil should reach the top of the thrust bearing.
15. Preparing for reassembly
Lubricate the O-ring for the oil chamber.
Before fitting the pump to the motor, make sure that the start/stop valve on the pump head is on the same side as the cutout for the screw (red arrow).
Fitting the pump assembly back onto the motor requires a bit of force since you have to compress the piston springs. Make sure that the motor is stable in the upright position before fitting the pump assembly.
16. Attaching the pump assembly
As soon as everything is aligned correctly, press the pump assembly down on to the motor. A fair amount of force is needed as you are compressing the piston springs onto the wobble plate.
When the two mating surfaces are in contact, twist the pump assembly 15-20° clockwise so that the two locks engages.
17. Secure the pump
Use the 4 short Allen bolts to fasten the pump to the motor.
18. Attach the new switch box
Attach the switch box to the pump. You may need to put quite a lot of pressure to get the box firmly seated on the start/stop valve. It should pop into place.
19. Reattach the power cables
Reattach the power cable by pushing the male spade connector into the female spade connector. Give them a light tug to check that they are securely connected. Make sure that the rubber cover is protecting the spade contacts to prevent short circuits and water ingress.
20. Reattach the grounding cable
Place the green and yellow grounding cable as indicated in the picture and then secure it with a Phillips/cross head screw.
21. Reattach the on/off button
Reattach the on/off button, its extension and the pump head cover.
22. Place the motor/pump unit back into the front cover
Carefully lift the motor/pump and turn it 180° before placing it into the front cover.
Make sure the on/off button and its extension are properly positioned so that they can operate freely.
23. Attach the water outlet
Attach the high-pressure water outlet to the pump head. Secure it with the U-pin. Some force may be needed to fully fit the U-pin.
24. Secure motor/pump unit to the front cover
Secure the motor/pump and the switch box using the 3 T25 screws.
25. Fit the back cabinet
Fit the strain reliever and make sure the power cord is correctly situated.
Place the back cabinet onto the front cover. Adjust so both parts align correctly. If you are having trouble to get a good fit, check that the power cables and motor cowling are aligned correctly.
26. Secure the back cabinet
Once you are happy with the alignment of the back cabinet, secure the front cover to the back cabinet with 11 T25 screws.
27. Fit the hose reel assembly
Fit the hose reel assembly to the back cabinet.
Push the interconnect pressure hose into the depression.
Fit the cover and secure it with 3 T25 screws.
Connect the hose to the outlet.
28. Reattach the water filter
Check that the filter cassette is clean and without damage.
Reattach the water filter to the water inlet.
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.
- Start by connecting the pressure gun to the hose.
- Connect water.Make sure no water is leaking from the inside or anywhere else on the pressure washer.
- Pull the trigger and let the water flow until there is no more air coming out.
- Connect the power cord.
- Turn on the pressure washer.
- Pull the trigger and let water run for a minute before connecting a nozzle.
- 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.
Motor is making a humming noise and is not able to start
- Check that the capacitor is connected to the motor.
- It should be connected with one white and one black cable.
