What's the best way to hook up a mobile pressure washer to a buffer tank

What is the best most effective way to hook up a mobile pressure washer to a buffer tank.

Don’t. Direct drive won’t work.

How should I set this up so I dont ruin the pump. It’s 3.5gpm

Just run a garden hose to it from the water faucet. You can’t hook it up to a tank. Don’t go more than about 60 seconds without spraying water.

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What happens if the hose puts out at less than 3.5gpm?

The reason you can’t use a tank with a direct drive like that is because it won’t pull water like a belt drive will. I suppose you could use a tank if you could get it high enough, forcing water into the pump via gravity. It would be a pain to do though and I’m still not sure if it would work.

I would do what Innocentbystander said and hook it up directly to the faucet. Most places will be plenty capable of 3.5 gpm, except maybe places with well water. Be sure to stay on the trigger too since you won’t have a bypass back to a tank to cool water down.

So as long as I dont let it run for longer than a minute it will be fine? Is there anyway that I can get it to pull from a tank?

Yes. Replace with belt drive

Help me understand why the same pump and same hp motor from a belt driven machine will pull from a tank, but a direct drive won’t.

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A direct drive pump runs at twice the rpm as a belt driven pump does. Don’t understand why the effects it pulling water but it does from what I’ve understood…

For what it’s worth. I run a direct drive off my buffer tank. I had some output problems at first and it turned out my carb was gummed up bad so I replaced it. I’m currently putting out just over 4gpm and 3800psi. It can be done. I’m gonna upgrade to a belt drive in the future but I’m going to run this motor and pump into the ground first. I service a lot of areas that don’t put our adequate water so a buffer tank is a necessity for me. I can post pics if you’re interested. Is it perfect? No. Does it work well? Yes.


Could you please post

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As @anon1966941 mentioned, it has to do with the speed of the pump. In order to make a pressure pump run at 3600 RPM and put out an appropriate GPM and PSI, the engineers had to change the internal geometry, with the plungers and shafts. There’s some fancy science and math involved, but the end result is that the high speed pumps don’t generate a vacuum like the lower speed pumps on belt or gear driven machines do.

But as @Alabama pointed out, there are ways of making it work. Usually an oversized input hose with no bends or restrictions, and a really solid gravity feed from the tank, are enough to make a direct-driven pump happy. If that doesn’t work, I would not recommend trying to use a booster pump; it’s a recipe for disaster.

I read somewhere that you might need to get the pump primed first by connecting to a garden hose to force feed the pump, and once it’s primed it will accept the gravity fed water from a tank. Don’t know whether there is any validity to that info.

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So my new 8gpm 3,500 psi can be ran off the tank only.
No 1 " garden hose from the house?

For sure. You just need a buffer tank because your machine is pulling 8gpm most residences put out 5-6gpm. Some as little as 3 around where I live. Without a steady supply of water you run the risk of burning up that nice new pump. @Fatdaddy

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I have a 275 gal tank. It starts as a 2 inch dump. Then splits 1 1/4 goes right with a ball valve so I can fill buckets or dump tank. The left goes from 2 inch to 1 1/4. To 1 inch filter then short hose. The only bend is the 90 tee off dump but it has a ball valve on the right to block water from going that way. I removed the factory filter off inlet and routed my bypass to the tank. This drastically reduced the turbulence and poor water volume at inlet. Here are some pics. I may still change out my inlet and put a 1 inch barb fitting there so I can run 1in hose instead of 3/4. But it’s running really well at this point so I’m gonna let it ride. It just takes some trial and error and figuring out what works best. As an added precaution I park where the nose of my trailer always tips down a little bit.

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Why do you have your DS “capped” off?

Just for when I have it parked or traveling. Guess I’m paranoid about a suicidal dirt dobber trying to make a home in it.


Alabama I have basically the same set up for my direct drive pressure washer. 2" reduced down to 1" right at pump with a short 3/4" hose connecting to pump (General pump) with a 320 gallon tote. Going on 2 years never have I had a issue will pull water tote empty. Plenty of water plenty of pressure.

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I have been pressure washing for a little over 5 years and I started out connecting to home or business for my water supply and most of my customers would jew me down on my price for using there water. Now I trailer all my water to the jobs and I charge full price $100.00 + an hour depending on the job higher the building higher my hourly rate. I think the difference in belt drive and direct drive is what you prefer. My thoughts only but my General pump has been going strong for 5 straight years 2 1/2 years on a water tote… I do change oil in pump and motor regularly. And same as yours bypass back in water tote. Im very happy

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