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Why Is My Pressure Washer Pulsating?

    why is my pressure washer pulsating

    The worst feeling is when you get out your pressure washer to complete a job only to discover that your pressure washer is pulsating. It may have bursts of intense pressure followed by long stretches of hardly any pressure at all. The job will take longer and you will end up using way more water. If you want a fun and efficient pressure washing, you want a constant flow of pressure that can push away dirt and grime. A pulsating pressure that stops and starts will only bring you frustration.

    Pulsating pressure washers could be a quick and easy fix or a sign of a larger problem. For this reason, it is important that you take caution and care the moment you feel like your pressure washer is not working as well as it should. There are also lots of easy care tips you can take in order to prevent a pulsating pressure washer. For this post, we will break down each section by problem areas that may result in a pulsating pressure washer.

    1. Kinks And Blockages
    2. Trigger Issues
    3. Pump Failures
    4. Plugged Nozzles
    5. Simple Tools For Pressure Wash Maintenance

    Check For Minor Problems Including Kinks Or Blockages

    If the water flow is restricted, there will definitely be surges and lapses in pressure. For every pressure washing task, you should always make sure that the hose does not have any kinks or leaks before use. This will undoubtedly mess with the pressure and potentially cause damage to your pressure washer. 

    A dirty inlet or discharge valve is the most common cause of a pulsating pressure washer. Dirt or hard water can get caught up in these little divots. It is important that you clean out these pieces every so often to prevent these kinds of problems. The general rule of thumb would be to clean the valve every 5 uses or so depending on the length of your pressure washing job. 

    Detergent suction can also create pressure problems for your pressure washer. If you find there is a significant amount of detergent build-up, you can run distilled vinegar through the detergent suction to get a better clean with stuck-on dirt and debris. 

    My Pressure Washer Trigger Doesn’t Work

    You set up your washer, pull the trigger, and all of a sudden it’s like the machine is not working at all. Luckily, pulling the trigger of your pressure washer will not cause it to magically shut down. There is an underlying cause to this common problem. It may seem like a no brainer, but if you do not use your pressure washer regularly you might not realize that sometimes you need to refill the fuel or oil. Just like a car, the pressure washer’s performance will be affected when fuel or oil is low or dirty. It is always a good idea to inspect the levels before starting the job to ensure the best performance. 

    Pressure washers can overheat, especially electric units. This could be from using it for too long of a stretch, or if the unit is being affected by the weather. The system will warm up the longer you use it, and this could be made worse when you are working in hot or humid weather. The best thing would be to rest your unit for thirty minutes and try again. 

    The unloader valve can be a neglected part of your pressure washer, but this is the element that most commonly contributes to that sudden shut off. Although you may forget that it’s there, it’s purpose is crucial to your machine’s performance. It allows the pressurized water to recirculate so it does not damage the pump. These can become clogged and drastically diminish the pressure. You can replace this part very easily but sometimes taking it out and putting it back in can be enough to clear up any issues. 

    Pressure Washer Pump Failure

    Pressure washer pump failure sounds like a disaster. Luckily, it does not mean you need to throw out your beloved pressure washer. If you start to notice lagging performance, or if your pressure washer is pulsating and is clear of kinks and clogs, you may want to consider giving the pump some TLC. 

    Air can become trapped in your pump, and this needs a quick fix. Simply turn off your pressure washer and disconnect the hose. Keep your garden hose attached and allow water to run through it for 20-30 seconds. Turn off your garden hose and reassemble. Try using your pressure washer as normal and see if that fixes the pulsing. 

    Conditions for the pump need to be right in order for your pressure washer to work properly. Keep in mind that some units need the inlet water supply at full force. Your machine might not seem like much of a pressure washer if only a small stream of water is going into the pump. Turn your garden hose on full force to allow more water into the pump. 

    What Do I Do If The Nozzle Is Plugged?

    When your nozzle becomes plugged or clogged, you will not have the same level of job satisfaction. You should regularly clean your nozzles to limit clogs. For most units, you can disconnect the spray wand and use a wire to push out clogs then flush it with water to remove debris.

    Clogged nozzles are inevitable over time, but there are a few reasons why they occur. First off, debris will build up over time. The more you use your pressure washer, the faster wear and tear will lead to problems for your unit. Caking can also occur when worn out materials build up within the nozzle, or with dirty water. Be mindful as well when using detergents as some can lead to erosion or corrosion if not washed out properly. 

    Keep in mind that not all nozzles are built the same. Pressure washers frequently have interchangeable nozzles that you can switch up depending on the job or surface you are working on. 

    There are a ton of handy tools and parts that you can use to regularly clean and maintain your pressure washer. Your pressure washer may come with its own cleaning kit, but you can be prepared to be equipped with any tools you might need to address clogs and other small scale issues.

    • Cleaner Wire
      • There are plenty of household materials you could use as a wire to clean out tiny crevices. From a stretched-out paper clip to the wire of a twist tie, there are some pretty innovative options. However, it can be stressful to find one of these tiny things when you are in a pinch and need to clean out a nozzle ASAP. Having a dedicated cleaner wire for your pressure washer in your toolbox can alleviate that stress and allow for quick fixes as you need them. We recommend this set from Petutu. It has a variety of cleaning wires and needles, which can work for a multitude of household items.
    • Pump Saver
      • A good pump saver can be your saving grace. The purpose of this handy formula is to support the piston of your pressure washer. You absolutely need a pump saver when storing your pressure washer for long periods of time. The best pump saver comes from Briggs & Stratton. 
    • Hose Extension
      • Hose extension might seem unnecessary. You are likely wondering how such a thing can protect your pressure washer when it can be so simple to move your machine to the areas you need to reach. Whenever you have to physically move your entire pressure washer, you are opening it up to potential damage. A heavy-duty hose extension saves you from having to lug the machine around to clean everything you need to reach and allows the unit to remain stationary. 
    • O-Ring Kit For Pressure Washer Pumps
      • O-Rings are the little rubber circles for your pressure washer nozzle. These may need to be replaced from time to time due to wear and tear. If you replace them quickly, it will save you tons of nozzle hassle later. A torn and worn down O-Ring can damage your nozzle. Keep it sealed, clean, and protected by keeping a stash of these around your workspace. 

    What If I Need A New Pressure Washer Pump?

    Replacing your pressure washer is not as complicated as it may seem. The pump can be switched out fairly easily. The biggest thing is making sure you get the correct replacement. You should always consult your user manual or the manufacturer’s website before replacing your pressure washer pump. It is crucial that you determine if your pressure washer has an axial cam or triplex plunger pump. 

    Not all pressure washer pumps are created equal, so it would be a frustrating process if you do not research the pump you need before selecting your replacement pump. I also need to note that a wobble pump is not replaceable. If you have a wobble pump pressure washer and none of the quick fixes work, you may need to replace your pressure washer. Luckily, these units are typically the baseline and inexpensive units. 

    To replace the pump, you first need to pull out the bad pump. After pulling out the spark plug, you should disconnect all hoses that may be connected to the pump. Usually, there are a few bolts that hold down the pressure washer pump to the rest of the machine. Remove those bolts and carefully pull the pump off the unit. 

    At this point, you will need to switch the thermal relief valve. This valve helps regulate the pressure washer so it does not overheat. Some replacement pumps will come with their own valve, but if your replacement does not you can usually use the old valve and attach it to the new pump.  

    Install the new pump just like how you removed the old pump. Attach it, tighten the bolts, and then reconnect the hoses and spark plug. 

    If you find that your new pump does not work as well as your previous pump at optimal efficiency, don’t stress. It may need to warm up for a few minutes, or you need to go back through the quick fixes to see if there are only problems affecting its performance. 

    Don’t Panic Over A Pulsating Pressure Washer

    Although a pulsating pressure washer might bring you a rush of anxiety, the good news is that it is hardly ever a sign that you need to replace your pressure washer completely. As we discussed in this post, take note of some of the simple problems that can lead to a pulsating pressure washer and create a checklist for yourself. It is a good idea to run through this checklist before every use so that you can prevent issues with your pressure washer in the long run. First, make sure that all the hoses are straight and not kinked. 

    Before powering it on, you should inspect all of the seals and O-Rings and look for signs of wear. Replace those before you start your job if they are looking a little worse for wear. Turn on your pressure washer and let it run for a few seconds. If you pull the trigger and nothing happens, run some water through it and see if that will push on any debris that might be blocking the system. If you continue to have problems, you can try a vinegar rinse. 

    If none of those quick fixes seem to help, consider looking into replacing the pump. Check back with Just Pressure Washers for more updates and tips on how to have the most efficient pressure washer. 

    3 thoughts on “Why Is My Pressure Washer Pulsating?”

    1. Hi – thank you for your blog and invite to help. My Nilfisk C120.3 pulses on idle. It operates perfectly well, with no pulsing. I have connected it to the tap with a very short hose with no kinks and no change, still pulses on idle. Any thoughts gratefully received!
      Thank you

    2. You want it to pulsate very fast like the deists when he cleans your teach, he uses pulsating vibrations with a water jet. it works for him.
      Then make one for cleaning concrete and old cars.
      Thank you for listening

    3. my karcher honda 5.5 is pulsating. I swapped out the carb but still no luck. is it a pump issue, and if so, how do i fix?

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