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Help fixing US Products King Cobra pressure drop off with spinner tool

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  • Help fixing US Products King Cobra pressure drop off with spinner tool

    Question: I am having an issue with a new purchase of a TH 40 wand. I bought a combo package which included the cobra detail tool and the new wand. I have a king cobra 1200 pro extractor. I have recently replaced all the seals, o rings, and plungers. When I connect the cobra tool to the machine the pressure gauge is showing 1100-1150 psi. When I connect the TH-40 wand the machine operates at 600 psi. Any thoughts as to what might cause this? Please help
    Heaven's Best Carpet Cleaning of Polk

    Answer: Three issues cause this.
    1. The in-bound filters are dirty. You have two filters on this machine. One at the bottom of the fresh tank and another under the hood. The flow rate of the filter is not keeping up with the demand of the pump and this causes pressure drop.
    2. Change out the spray jets to a smaller size. For the TH40 spinner wand the default jet size is 1502 and you should try 15015.
    This will increase your 'use pressure' by 25%
    3. Add the pressure feed conversion kit. This will add an average of 75psi 'use pressure' with all tools.
    4. Do steps 1 through 3 for best performance.

    Question: I think I may have a defective TH-40. I put new 0502 jets in my old TH-40 and my king cobra pushes it at 1200 psi. The new Th-40 is only running at 600 constant. I bought the new one as a backup and was planning on using it when I purchase a new portable next month. I understand there is some pressure drop but the psi on the two wands is just to far apart. Any thoughts other than changing the above items you mentioned in an earlier email?

    Answer: My first thought is your jets are the wrong size. If the cleaning machine works OK with the other original TH40 then the jets are too large on the new TH40. I mean regardless of what is stamped on the jet. You need to run an experiment and take the 0502 jets off the old TH40 and install it on the new TH40 and see what happens. It is a matter of physics. Once you know a pump can produce the correct psi and you are still having 'use pressure' issues, either the water is being starved off before the pump OR the jets are too large after the pump. I have seen miss labeled/stamped jets before. Please confirm your experiment results so we can forward to the factory for resolution/warranty.

    Related links:
    King Cobra Extractor

    Replace your pump head

    Valve repair kit

    pump plunger seal kit
    Last edited by Donald; February 27, 2014, 05:33 AM.

  • #2
    King Cobra Pro and SX12 pressure drop

    Hola e estrenado mi nueva maquina king cobra y la sx12 en mis pisos de Mosaico ,el quimico criptonita me a ayudado , Pero la precion de mi nueva king cobra me a preocupado solo tengo 800 psi con la sx12 de 1200 psi que marca el medidor ,me preocupa ! no quiero presentar el servicio a mis clientes comerciales con pisos real mente sucios ,quisiera saber como arreglo el problema , les agradeceria mucho su ayuda. Gracias

    Hello and released my new king machine cobra and SX12 on my floors Mosaic, the Kryptonite chemical me helped, but the water pressure on my new king cobra am concerned only I have 800 psi with the SX12 1200 psi marking gauge, I worry! not want to present my service to commercial customers with actual floors dirty mind, I would like to know the problem under com I would greatly appreciate your help.

    Answer: This is not uncommon and is normal for a suction feed machine. 6. factors contribute to this issue. 1. Air trapped in your plumbing. 2. Dirty filters. 3. Stuck pressure regulator or unloader. 4. Jet size is to large. You do how ever want to make sure that you do not have any air trapped on the inside of the plumbing by suction priming the water pump and making sure you have all your filters cleaning in both the bottom of the fresh water tank as well us inside the under the hood. After you have confirmed your two water filters are clean you will have to suction prime your pump. Watch the video at
    The process of cleaning the filters will install air in your hoses so suction priming the pump is required.
    Since your machine is brand new, I doubt your unloader is stuck. 5. You can confirm the head of the pump and unloader are working correctly by testing the machine with a smaller jetted tool. If the machine can achieve 1200 psi their is nothing wrong.
    6. The unloader set lock nut is set too low. Watch video at
    The default jet size on your SX12 ends in 02 This means each jet at 4000 psi is estimated to dispense up to 2 gallon per minute and since your wand as two of these jets, this would be up to 4 gallons per minute. Naturally this is not a 4000 psi pressure washer and is also not rated for 4 gallons per minute. Your machine has a Pumptec 356U pump installed in it and is rated up to 2 gallons per minute and up to 1200 psi if it is pressure feed. You are not pressure feeding this pump, you are suction feeding the pump. This means the pump has to suck the water out of the tank before it can push the water down the hose. A pressure feed system means the building pressure (usually about 75 psi) is being feed directly into the pump head. The actually 'use pressure' can be improved by as much as the building pressure. In other words, if you convert your machine to pressure feed your 'use pressure' might go from 800 psi with dual 02 jets to 875 psi with dual 02 jets after the conversion. You can also install small jets on your wand. Please consider the next size smaller 15015 jets.
    It sounds like you might be afraid to clean really dirty commercial floors because of the low pressure. Please note that agitation plays a huge role in cleaning performance. You should make sure you include agitation by either manual agitation, horizontal agitation or vertical agitation. A suction feed, cold, 1200 psi machine is not really going to aggressively pressure wash a floor so the use of agitation will improve cleaning results.
    In addition to agitation to improve cleaning results consider adding heat and/or more pressure (upgrade to pressure feeding your pump).
    Adding heat can be done with outside heaters that or propane, diesel or kerosene.

    Respuesta: Esto no es raro y es normal que una máquina de alimentación por succión . 6 . factores que contribuyen a este problema . 1 . El aire atrapado en las tuberías. 2 . Los filtros sucios . 3 . Atascado regulador de presión o de descarga . 4 . Tamaño Jet es a grande . Usted cómo cada vez quiere asegurarse de que usted no tiene el aire atrapado en el interior de la tubería por medio de succión de cebar la bomba de agua y asegurarse de que tiene todos sus filtros de limpieza , tanto en la parte inferior del tanque de agua dulce , así que estamos dentro el bajo el capó. Después de haber confirmado sus dos filtros de agua son limpias , tendrá que succionar prime la bomba. Ve el video en
    El proceso de limpieza de los filtros se instalará aire en las mangueras de manera que se requiere de succión cebado de la bomba.
    Como el equipo es nuevo , no creo que el descargador está atascada. 5 . Usted puede confirmar la cabeza de la bomba y del descargador funcionan correctamente probando la máquina con una herramienta más pequeña de hidromasaje. Si la máquina puede alcanzar 1200 psi su es nada malo .
    6 . La tuerca de seguridad conjunto descargador está demasiado bajo . Ver video en
    El tamaño por defecto en su jet SX12 termina en 02 Esto significa que cada chorro a 4000 psi se estima para dispensar hasta 2 galones por minuto y desde su varita como dos de estos aviones , esto sería hasta 4 galones por minuto . Naturalmente, esto no es una lavadora de presión 4000 psi y además no está clasificado para 4 galones por minuto . El equipo dispone de una bomba de Pumptec 356U instalado en ella y está clasificado hasta 2 galones por minuto y hasta 1.200 psi si es alimentación a presión . No estás presión de alimentación esta bomba , usted está alimentando la bomba de succión . Esto significa que la bomba tiene que aspirar el agua fuera del tanque antes de que pueda empujar el agua por la manguera . Un sistema de alimentación de presión significa que la presión del edificio ( por lo general alrededor de 75 psi ) está siendo alimentar directamente en el cabezal de la bomba . La realidad "presión uso ' se puede mejorar hasta en un edificio de la presión . En otras palabras , si convierte el equipo a presión de alimentar a su "presión uso " puede ir de 800 psi con doble 02 jets a 875 psi con dobles 02 reactores después de la conversión. También puede instalar pequeños chorros en su varita. Por favor, considere el siguiente tamaño más pequeño 15.015 jets.
    Parece que usted puede ser que tenga miedo de limpiar los pisos comerciales muy sucias debido a la baja presión. Tenga en cuenta que la agitación juega un papel muy importante en el rendimiento de limpieza . Usted debe asegurarse de incluir la agitación ya sea por agitación manual , agitación o agitación horizontal vertical. Una alimentación por succión , frío, 1200 psi máquina no es realmente va a presión agresiva lavar el suelo por lo que el uso de la agitación mejorará resultados de limpieza .
    Además de la agitación para mejorar los resultados de limpieza considerar la adición de calor y / o una mayor presión ( actualizar a la presión de alimentación de la bomba ) .
    Adición de calor se puede hacer con calentadores externos que o propano , diesel o queroseno .

    Example of a propane heater:

    Links: 15015 1/8" Vee jets

    Pressure feed conversion kit

    Example of water filter that is installed under the hood of your machine

    Pumptec 356u Pump that is used with most tile cleaning all-in-one extractors