Are Pressure Washer Pumps Interchangeable?

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A pressure washer pump is what allows the nozzle to spray water out at high pressure. So it should not be surprising if it breaks down due to wear and tear. Now the question is, can you replace it with any type of pump? Or do pressure washers need something more specific?

Pressure washer pumps are not universal. Check if your pressure washer has a triplex or axial pump. These two are not interchangeable.

In this guide you will learn what type of pump your pressure washer needs. You will also learn how to replace the pump and common installation mistakes to avoid.

What Pressure Washer Pump Do I Need?

The most common types used by pressure washers are axial and triplex pumps. Only one of these pumps will be supported by your pressure washer. There are many differences between the two but in general:

Axial pumps are commonly used in pressure washers designed for home use. It is more affordable than triplex pumps.

Triplex pumps are used for heavy duty commercial pressure washers. It can generate higher PSI than axial pumps and built to last longer. The AAA 90037 Triplex Pressure Washer Pump is one of the most durable and efficient available today.

Because pressure washers only support one pump type, you have to decide which you need. Let’s take a closer look at the differences between these pumps.

By the way, the pump is just one part. You also need to use the right pressure washer wand to get the best results.

What is a Pressure Washer Triplex Pump?

A triplex pump is found on professional and high end pressure washers. It supports at least 3000 PSI and is more durable than an axial pump.

A triplex pump can produce high pressure. With each stroke, a triplex pump pulls water in and out. With an efficiency rating of at least 90%, it is the best pump type available.

Triplex pumps last a long time because they utilize less RPM compared to the engine. The lower the RPM, the more efficient it runs. This also reduces the possibility of overheating.

If you need a high end pressure washer and a 3000 or higher PSI, a pressure washer with triplex pump is for you.

These pressure washers have durable components and are not vulnerable to leaks. The pump can handle continuous high water pressure and are very efficient.

The downside is the cost. A triplex pump is more expensive than an axial. But if you need this type of pump, it is a worthy investment.

What is a Pressure Washer Axial Pump?

An axial pump is found in mid-level pressure washers for home use. It is more affordable than a triplex pump but less efficient.

Axial pumps have a higher GPM and PSI compared to a wobble pump. Axial pumps are also called swash plate pumps because of the pistons that spin around it.

The swash plate is set so the pistons are able to stroke it. One side draws water and the other dispenses it. The axis spin is similar to the driveshaft, which enables bigger bearings and fuel tanks.

Compared to a triplex, an axial pump cannot match its power. But it is lighter and you can adjust the water flow. It is also self-priming. If you don’t need the power of a triplex pump, an axial pump will be sufficient.

Our pick is the Yamatic 3/4″ Pressure Washer Pump. It is easy to install, lasts a long time and delivers consistent results.

How to Replace a Pressure Washer Pump

This video demonstrates how to replace a pressure washer pump. If you want to follow step by step instructions, keep reading.

Step 1

Check what pump type your pressure washer uses. You also need to check what PSI and GPM the existing pump can handle. The replacement must be an exact match to this..

Turn the pressure washer off. Disconnect it from the power source if it is electric. Have all the tools ready and follow all safety precautions. These instructions are aimed as gas powered pressure washers.

Step 2

Disconnect the spark plug wire. Unplug all hoses linked to the pump. How many depends on the pressure washer, but the most common are:

  • Chemical injection tube
  • The water inlet hose
  • Spray outlet nozzle hose

Step 3

After the hoses are disconnected, you can take the pump out of the pressure washer. Use an Allen wrench equipped with a ratchet. Once the bolts are loose, hold the pump with one hand. Now loosen the other bolts.

Step 4

Install the new pump. This is the exact opposite of what you did. Hold the new pump with one hand and tighten the bolts. Next, put the rest of the bolts in.

Reconnect the hoses and the spark plug. Turn the pressure washer on. You might have to adjust some settings to get the pressure you want. But the machine should run.

Frequently Asked Questions

Why is the pressure washer pump not working?

If the pump is old, it could be due to simple wear and tear. Lack of maintenance is another factor. Axial pumps in particular need more care than a triplex.

Hard mineral deposits in water can damage a pressure washer pump. Check your owner’s manual for details about what type of water deposits the pump can handle.

Too much or too little pressure is another reason. Axial and triplex pumps run within a specific pressure range. If the pressure is too low or too high, it can damage the pump.

What is a wobble pump?

A wobble pump is the least powerful of all three pressure washer pumps. It is less efficient than an axial and doesn’t last as long.

A lot of entry level electric pressure washers use wobble pumps. They are the most affordable types but cannot be fixed. If the pump goes bad you have to replace it entirely.

When should I replace a pressure washer pump?

Replace the pump as soon as it no longer functions normally. With regular maintenance you should be able to see if there are cracks or other problems with it as well.

If we are talking about the average lifespan, it depends on how the pump is used.

The average lifespan of a triplex pump is 10 years, and an axial pump up to 8 years. But this assumes the pumps are well-maintained and used 3-5 hours a week.

Long usage times, lack of maintenance, the environment, temperature, water, etc. all affect a pump’s durability. Proper usage and regular maintenance makes any pressure washer pump last for years.

Can I upgrade my pressure washer pump?

You cannot replace an axial pump with a triplex. But it is possible to replace an axial with a better designed axial. As long as the pump can fit, it should work.

Do not attempt to upgrade from an axial to a triplex. The pump is not even going to fit in. If you want a triplex pump, you have to buy a pressure washer that uses it.

What are the signs of a broken pressure washer pump?

The most obvious sign is low pressure. If the PSI is low or irregular, there is a problem with the pump. A pressure gauge can point out if there is an issue. If the line does not hold steady, there is a problem.

A leak, tear or other physical problems can cause a pump to go bad. If the pump is running below expectations, it might be incompatible with your model. It could also be the pump is of poor quality.

You should also check the GPM. If it is below the advertised level, there could be a problem with the pressure washer.

Is it better to fix or replace a pressure washer pump?

It depends on the damage. Triplex pumps are easier to repair because of the available parts. But you should only attempt this if you are knowledgeable. Axial pumps are harder to repair. Once it is damaged, you are better off buying a replacement.