V4 02 Piston sealing repair kit
Applicable for:
- AVA Master: P60, P70, P80, both Master 1.0 & Master 2.0
- Evolution: P60, P70, P80
Recommended for qualified technicians – Always consider a complete module kit*
This kit contains essential seals located around the pistons and oil chamber in the pump. These seals are responsible for separating the water section from the oil-filled crankcase, keeping both systems isolated.
A damaged seal may cause water leaks, oil leaks, or water intrusion into the oil chamber — which can lead to performance loss and long-term damage.
The kit includes one oil seal (per piston), a high-pressure seal (per piston), and an O-ring for the oil chamber.
Note: These sealing elements are designed to match exact pump specifications. Replacing them with third-party parts may lead to improper fit or rapid wear. Always compare material and sizing carefully.
*Recommended for qualified technicians – Always consider a complete module kit.
Replacing internal seals requires disassembly of the pump’s piston unit and proper reassembly to avoid leaks or internal damage. If the machine has been exposed to frost or shows multiple symptoms, and/or you are unsure whether the leak is from the piston seal or a different part, we recommend using a full 10 Year Warranty and Repair Kit for a complete refresh.
See all our Warranty and repair kits here.
Typical cause of failure
- Natural wear from long-term use.
- Exposure to freezing temperatures (frost damage).
- Contaminated water leading to premature seal failure.
- Improper reassembly or incorrect seal orientation in earlier repairs.
Failure symptoms – Part correlation
- Visible water or oil leaks from the lower part of the pump.
- Gradual loss of pressure during operation after 5–10 minutes (caused by water mixing with oil).
- Milky or grey-coloured oil seen during inspection – a clear sign of water in the oil chamber.
- Performance drop that improves when the machine is cold, but worsens as it heats up.
Installation advice
Always prioritize safety first: Safety instructions – AVA of Norway
- Ensure you have considered the alternative above.*
- Disassemble the piston unit according to step by step instructions:
- Master guide: click here. Follow the guide to step 16.
- Evolution guide: click here. Follow the guide to step 13.
- Remove old seals and clean the piston thoroughly.
- Replace the oil seal in the aluminium guide plate with the open side facing the oil, and the slightly coned lip facing upwards.
- Replace the O-ring on the oil chamber.
- Insert the high-pressure seal into the valve housing first, then slide the housing over the piston shaft.
Tools Needed for all AVA Pressure Washer Maintenance – AVA of Norway
Warranty and Self-Repair – The AVA Way
At AVA, we encourage repair – not throwaway culture. You’re free to open your machine, inspect it, and replace parts yourself without losing your warranty. That’s part of what makes owning an AVA product different.
We offer guides, spare parts and support so that you can keep your machine running for many years to come – whether it’s a simple nozzle, a carbon brush, or a full pump module.
Many parts are designed to be replaceable – just like they should be.
Visible signs of use or repair are welcomed – they mean the product is being cared for.
Learn more about our warranty: AVA Warranty Terms & Conditions
Price includes VAT
V4 02 Piston sealing repair kit
Applicable for:
- AVA Master: P60, P70, P80, both Master 1.0 & Master 2.0
- Evolution: P60, P70, P80
Recommended for qualified technicians – Always consider a complete module kit*
This kit contains essential seals located around the pistons and oil chamber in the pump. These seals are responsible for separating the water section from the oil-filled crankcase, keeping both systems isolated.
A damaged seal may cause water leaks, oil leaks, or water intrusion into the oil chamber — which can lead to performance loss and long-term damage.
The kit includes one oil seal (per piston), a high-pressure seal (per piston), and an O-ring for the oil chamber.
Note: These sealing elements are designed to match exact pump specifications. Replacing them with third-party parts may lead to improper fit or rapid wear. Always compare material and sizing carefully.
*Recommended for qualified technicians – Always consider a complete module kit.
Replacing internal seals requires disassembly of the pump’s piston unit and proper reassembly to avoid leaks or internal damage. If the machine has been exposed to frost or shows multiple symptoms, and/or you are unsure whether the leak is from the piston seal or a different part, we recommend using a full 10 Year Warranty and Repair Kit for a complete refresh.
See all our Warranty and repair kits here.
Typical cause of failure
- Natural wear from long-term use.
- Exposure to freezing temperatures (frost damage).
- Contaminated water leading to premature seal failure.
- Improper reassembly or incorrect seal orientation in earlier repairs.
Failure symptoms – Part correlation
- Visible water or oil leaks from the lower part of the pump.
- Gradual loss of pressure during operation after 5–10 minutes (caused by water mixing with oil).
- Milky or grey-coloured oil seen during inspection – a clear sign of water in the oil chamber.
- Performance drop that improves when the machine is cold, but worsens as it heats up.
Installation advice
Always prioritize safety first: Safety instructions – AVA of Norway
- Ensure you have considered the alternative above.*
- Disassemble the piston unit according to step by step instructions:
- Master guide: click here. Follow the guide to step 16.
- Evolution guide: click here. Follow the guide to step 13.
- Remove old seals and clean the piston thoroughly.
- Replace the oil seal in the aluminium guide plate with the open side facing the oil, and the slightly coned lip facing upwards.
- Replace the O-ring on the oil chamber.
- Insert the high-pressure seal into the valve housing first, then slide the housing over the piston shaft.
Tools Needed for all AVA Pressure Washer Maintenance – AVA of Norway
Warranty and Self-Repair – The AVA Way
At AVA, we encourage repair – not throwaway culture. You’re free to open your machine, inspect it, and replace parts yourself without losing your warranty. That’s part of what makes owning an AVA product different.
We offer guides, spare parts and support so that you can keep your machine running for many years to come – whether it’s a simple nozzle, a carbon brush, or a full pump module.
Many parts are designed to be replaceable – just like they should be.
Visible signs of use or repair are welcomed – they mean the product is being cared for.
Learn more about our warranty: AVA Warranty Terms & Conditions
