Trailer set up question regarding water pump

I’m currently in part time mode and saving money to one day to get a trailer set up with 8GPM pressure washer set up. Right now I’m just researching A LOT and watching videos on different trailer set ups. One question I have no one mentions anything about a pump from the buffer water tank to the p washer unit. Is it not needed or most y’all just use gravity fed method??

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It is not needed.

a belt driven or gear driven pressure washer will suck water from the tank on its own, no pump necessary. A direct drive machine will need to have a pump feeding it , which means you will need a generator to run the pump ( or a long extension cord). the extra $ for pump, plumbing power source etc will cost you more in the end than just buying a belt drive from the start.

Gotcha now it makes sense.

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I’ve gravity fed my direct drive 5.5gpm unit for 3 years now with no problems. That’s even with just a 15 gallon induction float tank.

Gravity fed works for all pumps but to pull water from the pump it needs to be either belt or gear driven. Surprised your direct drive pump has lasted that long. I had 1 direct drive pump and after my guys used it for around 10 straight hours on a Job it crapped out. Never again for us.

Yeah some feed with no problem as long as the water level is above the inlet. I had a 4.6 General pump EZ3045G that worked off a tank.

Found this old thread and have a question regarding the gravity feed. I currently use a Graco 3040, 4gpm, 3000 psi with a 11 hp Honda engine. Seems like when I start a job with a full 275 gallon water tank the pressure is sufficient but when I get down to about a 1/3 of the tank left the pressure is so low it is hard to wash let alone reach with any height. Is this normal with a gravity fed setup? I also have to set my pressure to the maximum or close to it from the start to have enough pressure to wash a house. Also wondering what kind of pump I could get to install between the tank and the PW to help with the water feed to the PW?

Find a good business in your area that knows about pressure washing. I started out with little experience, no real knowledge of equipment or process. An excellent distributor/shop showed me the way. After 13 years, still do ~ 95% of my business with them.

Is it a direct drive? If it’s not belt or gear driven, it won’t pull water.

(99.99999% of) Direct drive pumps need at least a little bit of incoming pressure to feed them. That would explain why it works ok until you get down to a certain level…The weight of the water is supplying enough pressure to feed the pump up to that point, but after that it’s just not enough.

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Exterior Cleaning Specialists
North Carolina

My Graco is a belt driven PW. I forgot to add that in my post.

I have a direct drive, also gravity feed, no issues here, of course I never let it run dry, but even on low water were good…

If you have direct drive then junk it and at the very least get a gear driven pump. Direct drive is for “Joe the homeowner” and not “Joe the businessman”

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Why would I junk something that feeds me? Still works! Still has life!

I see things differently, I will run it til it dies, get every penny out of it, once that happens I can do a belt drive, not to mention, I still don’t have big jobs that call for a bigger machine… I use to be that guy, who wanted the biggest the newest and the baddest, and life has shown me to take steps at a time, works better out for me at least…

If Direct drive works for you then have at it. Id suggest to start saving for a better machine and use that one for a backup. As for me I cant afford to be shut down on a job and I Direct Drive pump would easily crap out on us considering we work long days & I have employees.

The trailer I have came like this, Direct Drive… Its an older style trailer, but I have a belt drive portable pressure pro too, when my direct drive goes out, I will mount my belt drive…


Odd name. Anyway, don’t sweat it. Make $ with what you have. I started out on a whim with a 2.3 gal./min. direct drive POS Northern Tool PW the first year. Made and saved enough that the following Spring, purchased a 5.6 GPM Hydroteck , AR pump, belt driven PW that we still use today.

But again, we only service exterior wood. Start small with little capital, and grow. It is the American way.

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It works for me! When I grow out of it, Ill get a big boy machine… But for now, it does great. Its a 4gpm 4k psi so its not that bad… Longevity is the real question. And it has heat so I’m ok for now…

Hey guys. Reading through this post and questions I hope aren’t too stupid. Just want to make sure I do this right.

I have a 300g leg tank, 4GPM direct drive PW. The tank has a faucet that I can screw a hose into.
•Would a 100ft construction hose suffice?
•Will I need a filter or not since the PW already has an inlet filter?
•If I were to gravity feed, do I just make sure the tank is above the PW? Not entirely sure how that works.
•if I went the pump and generator route - What pump or generator do you guys recommend?

Thanks in advance!

What do you mean by construction hose?

Get rid of the inline filter and get a real filter. Those inline screens won’t stop smaller particles of sand, dirt, etc. Many install one before the tank and between the tank and the pressure washer.

Some say you can’t use direct drives off of water tanks and others say you can. If you do make sure your inlet hose is plenty big. I would go at least twice the size of the inlet on the pressure washer. As long as you can gravity feed enough water to keep up with the demand of the pump I don’t see why it wouldn’t work.

You’re going to need a Hudson float valve. You said you can screw a hose into your tank but what happens when you let off your trigger and the water keeps filling up your tank that’s already full? Not sure if you plan on hauling water to every job but I wouldn’t want to unless needed. If you decide to make sure your trailer can support the weight of the water and your equipment. You’ll definitely need a dual axle trailer for hauling 300 gallons plus equipment.

Better yet, since you’re running a 4 gpm pressure washer don’t even worry about the tank and just hook right up to your pressure washer. You shouldn’t even need a buffer tank unless water supply is horrible in your area. If and when you upgrade to a 5.5 or 8 gpm then you’ll want a buffer.

I’ve yet to see anyone on here run a pump to pump water from their buffer tank to their pressure washer. Maybe some are though.