Pressure Washer Pump Problems & How to Fix Them
If your pressure pump is losing pressure, pulsing, or won’t start, it could be due to air leaks, faulty switches, or worn-out parts. Check for obvious issues like blocked filters or leaks first. Some fixes are DIY-friendly, but electrical or internal faults may need a professional.
If the pump is old or frequently failing, replacement might be the most cost-effective long-term solution. We’ll look at the most obvious causes below, and step you through when prevention, DIY checks and when it’s probably time to call a highly experienced pressure washer pump repair centre.
Dealing With Pressure Washer Pump Problems? Let’s Get Started On A Fix
Understanding how your pressure washer pump works is essential to keeping your system running efficiently, and knowing what to do when it breaks down! Regular maintenance not only prevents common issues like low pressure or sudden pump failure but also helps extend the life of your equipment.
This guide will explain the most frequent pressure washer pump problems, how to identify them early, and practical steps for fixing or preventing them so you can get the job done without unnecessary downtime or costly repairs.
First, A Pressure Washer Pump Overview
The pump is the core of any pressure washer; it’s the component responsible for creating the high-pressure water flow that makes cleaning fast and effective. Without a properly functioning pump, even the most powerful motor won’t deliver results.
Several types of pressure washer pumps exist, including:
- Wobble plate – Common in light-duty electric washers. A subtype of axial design using a wobble plate to move pistons.
- Axial pump, axial plunger pump or axial cam – Often synonymous with wobble or cam pumps. A type of axial pump where pistons are driven directly.
- Triplex plunger pumps – These pumps have three plungers, offering smoother flow and greater durability. They are ideal for professional and industrial use.
- Duplex plunger pump – Two pistons, less standard than triplex, but still used in specific applications
No matter the type, if you don’t maintain the pump, you’re asking for trouble. Check the oil, clean the filter, and don’t let it run dry. Store it properly, cool, dry, with no water left inside, and it’ll return the favour with solid performance.
Knowing Your Basic Set-Up
A basic understanding of your pressure washer’s internal pump components is essential for troubleshooting and regular maintenance. Knowing what each part does and how to spot early signs of wear can save you from costly repairs and unexpected breakdowns.
Key pump parts to be aware of include:
- Pump Head: The main body of the pump where pressure is generated. Cracks or corrosion here can lead to leaks and pressure loss.
- Inlet Filter: This filter prevents debris from entering the pump system. A clogged filter can cause low pressure or internal damage.
- Valves: Control the flow of water through the pump. Worn or sticking valves often lead to pulsing pressure or total pump failure.
- Seals and O-Rings: These prevent water or oil from leaking out of the pump. Over time, they can wear out, leading to drips or reduced performance.
- Oil Reservoir: Keeps the pump lubricated. Low or dirty oil can overheat and damage internal components.
Routine checks, like inspecting seals, monitoring the oil level and cleaning the inlet screen, help keep your unit running smoothly and extend the life of your equipment.
Need help with your specific pump model? Always refer to your user manual or consult a technician for safe repairs.
Store Your Pressure Washer Properly To Avoid Pump Issues
Storage also matters. Always drain all water from the pump after use to prevent freezing and internal damage. Store your pressure washer in a clean, dry location away from moisture and dust.
Proper storage helps protect against corrosion and long-term wear, which are common causes of premature failure and can significantly shorten your pressure washer’s lifespan. Taking these simple precautions keeps your equipment reliable and ready for use.
Look After the Oil & The Pump Will Look After You
The oil in your pump isn’t just for show; it keeps everything moving smoothly. Ignore it, and you’ll soon have a pump failure.
Oil tips:
- Check it every 20 hours of use – Make it a habit to check it before use.
- Change it every 50–100 hours – Don’t wait for the oil to go black or smell burnt.
- Use proper pump oil (not engine oil) – Follow what’s in the manual.
- Look for leaks under the unit – Drips under the machine could mean seals or O-rings are on their way out.
If the oil’s milky or smells burnt, it’s done. Drain it and start fresh.
Troubleshooting Low Pressure Issues
Low pressure is a common issue with pressure washers, often caused by a clogged nozzle, insufficient water flow or pump failure. Checking the pressure gauge and ensuring an adequate water supply are essential steps in troubleshooting low-pressure issues.
Inspecting the high-pressure hose and nozzle for blockages or damage and checking the pump oil level can help identify the cause of low pressure. Cleaning or replacing the clogged filter and ensuring proper pump maintenance can help resolve low-pressure issues. If problems persist, consulting the machine’s manual or seeking professional repair may be necessary to prevent further damage.
Need help? Bring it in. Whether it’s pump repairs, parts or a new setup, we’ve got the know-how to get you back in action.
Pressure Washer Pump Repair Options
Repairing a pressure washer pump can often be a smart, cost-effective alternative to full replacement, particularly when dealing with older units or minor wear and tear. The key is accurately diagnosing the issue before deciding whether repair or replacement is the most practical solution.
Common fixes may include replacing worn components like o-rings, seals, or valves, which can restore performance without major expense. These parts are often readily available and can be installed with basic tools and a little guidance from the user manual.
For more complex issues or internal damage, it’s wise to consult a professional technician or the equipment manufacturer to avoid worsening the problem or voiding warranties. A correct repair not only resolves the immediate issue but also extends the life of the entire unit. Above all, regular inspection and preventative maintenance remain the most effective ways to reduce the need for repairs and keep your pressure washer running efficiently.
Common Pressure Washer Problems & Troubleshooting
Many common problems, from loss of pressure to startup issues, can be fixed with a few simple checks. This guide covers the most frequent issues, what causes them, and how to get your pressure washer working again.
Low Pressure (It’s Just Not Doing the Job)
Low pressure is the most common issue we see. If your washer suddenly feels weak, here’s what to look for:
- Check the nozzle – It could be clogged. Clean or replace it.
- Water supply – Make sure you’ve got enough flow. Pressure washers hate being starved of water.
- Inspect the hose for kinks, splits or blockages as they all impact your pressure levels.
- Check the oil level in the pump, as low or dirty oil can mess with performance.
- Dirty inlet filter? Clean it out, as debris in the system = bad pressure.
Still not right? Grab the manual or give us a call. Better to sort it now than burn out the pump.
Pump Not Engaging (Motor On, But No Spray)
If the motor runs but the spray won’t start, your pump may not be engaging properly.
- Test the trigger gun – Try using a different one to rule out a faulty trigger.
- Unloader valve – It could be stuck. Clean or replace it to get things moving again.
Still stuck? It might be time for a professional inspection.
Water Leaking From the Pump
Water leaking from your unit means something’s worn or cracked inside the pump.
- Check seals and O-rings – These wear out over time. Replace any that look damaged or degraded.
- Pump housing – Inspect for cracks. A damaged housing usually means the pump needs replacing.
Fix it early to avoid internal rust or further damage.
Oil Leaking From the Pump?
A small oil leak can quickly turn into a big problem if ignored.
- Oil seals – These are usually the culprit. Replace if worn or cracked.
- Overfilled reservoir – Too much oil can leak under pressure. Drain down to the proper level.
Tip: Keep an eye on oil levels during regular maintenance checks.
Strange Noises or Vibration (Something Feels Off)
If your pressure washer sounds louder than normal or is shaking more than usual:
- Air in the system – Bleed the system to remove trapped air.
- Worn bearings – These can grind or squeal. Replace if needed.
- Low oil level – Check and top up with the correct oil type.
Persistent noise? Book a service before internal parts are damaged.
Pump Overheating (Too Hot to Touch)
Overheating reduces lifespan and can ruin seals or valves.
- Dry running – Always make sure water is flowing before starting the unit.
- Blocked ventilation – Keep vents and fans clear for proper airflow.
- Wrong oil – Use only the oil type recommended by the manufacturer.
Pro tip: Never let the machine idle too long without spraying; it heats up fast.
Sudden Loss of Pressure (It Was Fine Before)
If your pressure disappears mid-job, check for flow issues first.
- Inlet filter – A clogged filter blocks water entry. Clean or replace it.
- Hose kinks – Straighten or replace any damaged lines.
- Unloader valve – This may be stuck open. Clean or service it.
If pressure is still inconsistent, a pump service might be needed.
Pulsing Pressure (Surging On & Off)
Surging water pressure usually means your machine is struggling to regulate flow.
- Blocked nozzle – Clean or swap it out. A partial clog can cause surging.
- Air leaks – Tighten all hose and fitting connections. Check for cracks.
- Worn pump valves – These can stick or fail to seal correctly. Service or replace them.
Still pulsing? It’s best to get a technician involved before more wear sets in.
Pressure washers are one of those machines you don’t think much about until they stop working. Whether you’re blasting grime off a driveway or using a heavy-duty washer on a job site, your pressure washer needs to run smoothly to do its job. That means keeping an eye on the pump, the oil, and the hoses and knowing how to fix issues before they become headaches.
Fixing A Broken Pump – Repair or Replace?
Sometimes, it’s not worth binning the pump just yet. Small issues can often be fixed.
- Worn O-rings or seals? Cheap to replace, easy to fit.
- Suction problems? It could be the unloader valve or the water supply.
- No pressure at all? It might be time to call in a pro, especially if the pump has been running dry or overheating.
If your machine’s older or has been pushed hard, a new pump might be the smarter move. We can help you weigh it up.
DIY vs Pro Repairs – When to Call It
Simple stuff like blocked nozzles, dirty filters, and worn seals? You can handle that.
But if your pump has:
- Cracked housing
- Internal scoring
- Bearings or pistons are worn out
…then it’s time to bring it in. We can tell you if it’s worth repairing or if a new pump’s the smarter option.
Don’t Be Slack on Maintenance
A pressure washer is like any other tool. If you look after it, it’ll work hard for you. Ignore the signs and skip the maintenance, and you’ll soon be forking out cash for repairs or replacements.
Keep it simple:
- Check oil and filters regularly
- Inspect hoses and seals
- Store it dry and clean
- Fix small issues before they become big ones
Final Word
A pressure washer pump doesn’t ask for much; it just requires clean water, the right oil, and a bit of routine care. Stay on top of maintenance, and small issues won’t turn into big, expensive ones.
Still stuck or need help diagnosing a fault? Swing by or give us a call, or check out some more tips for keeping your pressure washer at its best. We’ve seen it all and fixed most of it. Melbourne Jetter Centre – for pressure washer sales, repairs, parts, and straight-up advice that actually helps.
