Pressure Washer Leaking From Pump? (Possible Causes & Fixes)

Ossiana Tepfenhart
by Ossiana Tepfenhart

If you need to clean a deck or get mold off of siding, chances are you are going to need a pressure washer. Pressure washers are remarkably useful things and can be used to clean a bunch of things. Of course, they’re only useful if they work. When the pressure washer’s pump is leaking, they don’t really do much, do they? You probably should know what this means for the washer and how to remedy the issue.

A leaky pressure washer can have multiple reasons for its problem, especially if it’s directly from the pump. In most cases, the leaking is caused by one of the following things:

  • Broken Seals
  • Cracks In The Pump
  • A Bad Thermal Release Valve

Pressure washers that are leaking aren’t just hard to use. They can actually be a danger to people around you in some cases. This guide will help you figure out what’s going on with your washer, and how to fix it.

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How To Diagnose A Pressure Washer Leaking From The Pump

The good news about this issue is that we can jump right into the troubleshooting fairly easily. To figure out where the leak is easier, we are going to parse things out by the issues.

Note: Due to the difference in many pressure washers, we cannot give full step-by-step instructions on how to troubleshoot everything in all cases. To access the pistons or work with the interior of your pressure washers, consult your owner’s manual or call a repairman.

Broken Seals

There are three main groups of seals that can cause a leak from your pump. First, look at the sealed rings that are around the pressure machine to the hose. Are they okay? If they’re not, that’s the leak source. Replace the outlet seals and you should be alright.

The other seals that can fail are the piston seals inside the machine. When you open up your pressure washer, look at the pistons. If you see that a rubber seal broke, that’s the part you will need to replace. If you do not feel comfortable getting to the pistons or don’t have adequate instructions

Cracks In The Pump

In order for the pressure water to work, your washer will need to pump water at a high pressure through the hose. Unfortunately, certain conditions can make your pump crack. When you look at your pressure washer pump assembly, you should see the metal has a solid build. If you notice cracks on the outside, you need to replace the pump assembly.

It’s worth noting that not all cracks will show on the outside of the pump. If you believe that there could be a crack you don’t see, then you need to consider replacing the entire model or risking extra money wasted. It’s a tough call.

A Bad Thermal Release Valve

Your pressure washer’s thermal release valve is meant to regulate the temperature and pressure of the water in your washer. When it goes bad, it can cause cracks in your pump. At times, the valve itself can leak, making it appear as if the leak is really originating in the pump rather than the valve.

A thermal release valve is thankfully inexpensive and easy to replace in most cases, which means that you can usually give this a quick try to see if it works.

How Bad Of A Problem Is This?

A leak at the pump is not a laughing matter, nor is it something you should ignore. Leaks near your pressure washer’s pump can cause a wide range of problems, including:

  • You could find yourself losing water pressure. A leak can easily turn your pressure washer into a glorified hose. This is actually one of the most common symptoms that makes people check out their pressure washers in the first place.
  • The pressure washer could stop functioning altogether. Though rare, some pressure washers had emergency stop valves. If you have a crack in the pump, you could trigger certain safety functions to shut down the pump.
  • Or, the pump could explode. If the leak causes water to start contaminating the pump, the pressure could be too much for the pump to handle. This could cause a potentially lethal explosion that sends shrapnel flying everywhere.
  • The leak can also reduce the reach of your washer. Lower pressure means that you won’t be able to get the water to reach further. This can make it hard to get into small corners or high up on a building.

Should You Replace Your Pressure Washer?

Technically, this is not usually an issue that could require a full replacement. If you really want to (or just have a super-pricey washer) you can buy individual parts and switch things out. However, many people find replacement to be a very labor-intensive endeavor. If you have a cheap washer and would rather just replace the washer, that’s understandable.

Still, most people would be better served by some DIY repairs or better still, professional repairs. The only time that you really need to consider replacement over repair is when the cause of the leak is a broken pump or if you need to replace multiple parts. Pressure washers don’t last forever, so if you feel like yours is on the way out, that’s 100 percent okay.

How Much Does It Cost To Replace Your Power Washer?

If you want to replace your power washer, then you have a wide range of price ranges you can choose from. Basic, home-only power washers will cost between $100 to $300 for a low-end machine. Midrange models can cost between $400 to $800 and are often better off repaired.

If you have a pressure washing company and have a professional-grade machine, what on earth are you doing reading this article? Professional-grade pressure washers start at $800 and can be upwards of $2400. If you own one, your best off trying to get it repaired by a professional repairman.

How Much Does It Cost To Replace Your Power Washer Pump?

Frugal pressure washer owners will want to know how much they should expect to pay on parts. The pressure washer pump is one of the most expensive parts of the machine, which is why we’re going to start talking about the pricing for these particular items. Pressure washer pumps can range between $20 to over $150, depending on the quality of the pressure washer and the scarcity of parts.

A good rule of thumb is that you should expect the price of your power washer pump to be the priciest part of a repair and that it should be viewed as the “ceiling” of repair prices. If repairs somehow cost more than that, you need to ask yourself if it’s even worth it.

Does It Make Sense To Repair Your Pressure Washer?

We honestly don’t know whether or not it’s going to be. Pressure washers are fairly cheap, especially if you just need to get one for casual use. It all depends on the price of your pressure washer versus the price of your replacement parts. If the parts and labor are worth 1/2 or more of the total price of the washer, you might want to replace your pressure washer.

On the other hand, professional-grade pressure washers are better off repaired. If your power washer has a warranty, it also makes sense to call up the manufacturer to see if you can score a free repair.

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Related Questions

How many PSI should I buy in a pressure washer?

It depends on what you want to do with it. If you need to wash a car using a pressure washer, 700 PSI should be fine. Most typical home projects will need between 1,300 to 1,700 PSI to be done correctly. That’s great, since that’s approximately the minimum a typical pressure washer will offer in their stats.However, if you want to do a deep cleaning on something along the line of concrete, then you will need 2,200 to 3,000 PSI. Even so, most people will be able to enjoy some results with a standard washer.


Is 3000 PSI too much for a car to handle?

How many PSI you can use to pressure wash a car depends on the nozzle that you use. If you use a  nozzle that concentrates the force on a single point, 3000 PSI will probably damage your car. However, if you choose a pressure washer nozzle that spreads the water out over a wider range, you probably could use 3000 PSI.With that said, you always should take sensitive car paints into consideration. When in doubt, go for a lower pressure even if you think your car could handle it.


Is using a pressure washer on a car a bad idea?

Not always. Many people use power washers on their cars with great success, especially if your car recently had a pretty bad run-in with dirt and mud. However, if used improperly, you might see your pressure washer cause damage to your paint. Unusually high pressures or a mishandled hose can lead to nicked, chipped, and cracked paint on cars. Avoid using it on vintage models!

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Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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