Is your pressure washer pulsating? Here’s what to do!

It’s terribly inconvenient when you’re getting ready for a day of pressure washing only to find that yours has inconsistent flow and is pulsating like crazy. This might be the reason behind it!

One of the most common reasons for a pressure washer to pulsate (or the flow of water is inconsistent) is because there is a clog or a kink somewhere between the nozzle and the water source. Finding and removing the obstacle or blockage is a surefire way to stop the machine from pulsating.

There could be more than one reason for your pressure washer’s malfunction. Here are a few other good things to be aware of!

Common causes

As mentioned above, clogs are a recurrent reason for a pressure washer to pulsate and sometimes shut down. One of the first things you should check is the hose. If there is a kink or leak in the hose, the water flow will lose a lot of its power and simply will not get the job done. Depending on the severity of the puncture, the hose will either have to be repaired or possibly replaced.

It is also possible that the nozzle is the source of the clog. Dirt and debris will occasionally build up in the nozzle and sometimes behind the water inlet screen. Both ought to be cleaned and checked regularly (ideally after every use) to prevent this kind of blockage.

The trigger could also pose a problem for you. If the trigger is broken in any way, chances are your flow will be inconsistent. A malfunctioning trigger could be the result of another problem, however. Engines are susceptible to overheating at some point or another. This can happen if your unit is left outside in the heat for too long. It can also happen if you have been overrunning your machine. Many pressure washers cannot run for more than 8-10 minutes at a time, and exceeding this limit will cause the engine to shut off. It is also possible that you need to do something as simple as refilling or topping off the fuel tank. If your machine hasn’t been used for a long time, there is every chance that you need to put new fuel in it.

Having an insufficient water supply or cavitation might also make your pressure washer pulsate. It will force the machine to work harder than it should have to and that could cause even further damage. If this is not the problem, you may have worn pump packings that might need replacing.

Additionally, you may have a pump problem. Like any other machine, pressure washer parts will wear out eventually. There is every chance that your pressure pump is failing. As inconvenient and disastrous as it sounds, all is not lost. Either a part needs fixing or you might just have to replace the entire pump. Sometimes it’s something as simple as air getting trapped inside the pump which means you’ll have to shut the washer off, disconnect the hose, and let water run through the system for 2-3 minutes.

Finally, your unloader might have a problem. The unloader’s job is to relieve pressure when the spray nozzle gets blocked at any time. If it gets stuck or restricted in any way, it will just lie above the water inlet without doing what it’s supposed to. It should be repaired and replaced as often as is necessary.

Quick fixes

Each one of the problems listed above might be inconvenient, but each one has a solution. Clogs and leaks are no big deal! Clogs occur mostly in the nozzle and behind the water inlet screen. Simply remove the nozzle and hose and clear the debris. It is advisable to first clear out the debris and then run water through the system for a minute or two. This will ensure that nothing has remained inside to clog the inlet screen. If you are having trouble unclogging your nozzle, that might mean that it is too worn out and needs to be replaced. Additionally, the hose could have sprung a leak and will either need to be patched or replaced.

If your trigger does not appear to be working, consider shutting the pressure washer off for a while before assuming the trigger is broken. It is possible that your washer’s engine is just overheated and needs a break. To prevent this from happening, do not run your washer beyond its limit, and try to avoid keeping it in direct sunlight. If an overheated engine is not the problem, there is every possibility that your trigger is in fact broken and needs replacing.

Pump failure, while problematic, is a fixable issue. If your pressure washer starts to pulsate, consider checking your pump for problems. You can try letting the air out of it, which means you’ll have to disconnect the hose and let the water run through and out. If this does not work for you, remove the pump from the washer’s body and inspect it for damage. If it is too dirty or worn down in any way, you will probably need to replace it.

Check your valves! If your discharge valves are dirty or blocked, water will not flow the way it ought to and that will cause problems. The inlet valve(s) allow water to enter the manifold; if no water is coming in, there is every chance that this is what is causing your washer to pulsate. If the valves have been cleaned/fixed and the washer is still not working for you, you might need to fix or replace your valve spring.

Checking your unloader could resolve the issue as well. Make sure there is no unnecessary pressure in your unloader. It is a good idea to replace your unloader as often as is necessary, but you might consider simply taking it out, letting it sit, and then putting it back in again. Sometimes that is all that’s required to solve the problem. Additionally, the hose could have built up stored inside it as well. To fix this, detach the hose and let it sit for a moment before reattaching it to the machine.

Preventing the problem

We have explored ways to fix problems that might be encountered with a pressure washer. Here are a few ways to avoid these problems as much as possible.

An overheated is a common problem and it is a likely cause for pulsation in your pressure washer. If it has been overworked, it is likely that the washer will quit on you. Depending on how often you use your washer (for instance, if you have a job in pressure washing) you might need a specific type of washer. Most professional equipment has a longer endurance period than common household pressure washers, most of which cannot run for more than 10 minutes at a time. Make sure you are aware of how long your washer can run before using it.

The pump will need replacement at one point or another, but you can prolong your pump’s life by lubricating it with a protectant or pump saver. Briggs and Stratton’s pump saver is a notable product that is particularly good if you are planning to store your pressure washer for long periods of time. Protecting your pump while in storage is a must. Failure to do so can result in a dirty, worn out pump that will need frequent repair and/or replacement.

Cleaning not only your valves but additional parts (such as the hose, nozzle, and oil filter) on a regular basis can help to prevent the need for constant heavy duty maintenance. It might take time and effort, but diligently cleaning out the valves will keep your washer in good repair and will lessen the necessity of frequent repair. A good rule of thumb is to clean valves and inlets every 5 uses or so. This will, of course, depend on the length and frequency of use. If you are using your pressure washer on a daily basis, cleanings might be required more often.


Finally, here are a few tips to keep your washer in good repair. Possibly the most important thing you can do is to change the oil as often as needed (which is usually every three months for most pressure washers). Failure to change dirty oil will result in a smoking, overheated engine as well as a dying washer. If you are unsure of when you ought to change the oil, you can call the manufacturer, consult the user’s manual, or check the oil for particles or a dark or cloudy color. Regardless of when you last used it, it is generally a good idea to change the oil right before you put your washer into storage. This will ensure that the engine is well lubricated throughout the winter months and will be ready to go once you pull it back out for use.

Lastly, make sure you have enough fuel and water running through your washer’s system. An insufficient fuel supply will not be a huge problem, it will just cause your washer to fail. Don’t overfill the fuel or oil tank however; doing so will cause spills which could potentially damage your engine. An insufficient water supply, will definitely be more problematic. It will cause your washer to work way too hard, and it won’t get the job done because there will be a severe lack of pressure.

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