Question about pressure washer pumps...

[Nick Chapman]

I bought a Karcher pressure washer a while ago, and just recently hooked it up to my 90 gallon water tank, gravity fed.
Pressure washer has always worked great. Now the water surges coming out of the gun, and I'm assuming it's because of the pump. Do all pumps do this? Would it be bennificial for me to get an outboard pump to supply the pressure washer, or buy a different pump to mount on the pressure washer?

Thanks,
Nick

[Tim Lingor]

Re: Question about pressure washer pumps...

Hi Nick,

No , the pump should not be surging like that. They should be able to keep a relatively constant psi/gpm.

You say that it is gravity fed from your on board tank. The problem is that pressure washers require a certain inlet water pressure from the source for the pump to work correctly. If the flow is too low, you may end up burning up the pump. Your owner's manual should tell you what your minimum water inlet pressure is... After that, you may have to place some type of inline pump to boost the water pressure to the washer.

Good luck and please keep us posted.

Tim

[Nick Chapman]

Re: Question about pressure washer pumps...

Well, when I bought this pressure washer, I made sure that it had a pump strong enough to work for me(gravity fed tank). Karcher said that this one would syphon water out of a pond with the right house(which I bought). This is the first time I have used the pressure washer with my tank, and it's kind of frustrating. Guess I'll have to call them and make sure I didn't get a bum unit.

[Nick Chapman]

Re: Question about pressure washer pumps...

It has an Axial pump if that makes any difference.

[Tim Lingor]

Re: Question about pressure washer pumps...

Hey Nick,

Is your Karcher gas powered or electric?

There will be some draw from the pump, but even with my gas powered unit, it has a warning to make sure I have a strong enough inlet pressure to avoid burning out the pump.

I would suggest that you call the company and ask what they advise. Also make sure that the pump is not overfilled with too much oil (that can also make the pump act goofy)

Sorry, I wish I could have helped more.

Tim

[farmboy]

Re: Question about pressure washer pumps...

Is it possible that air wasn't bled out yet? I usually hold the trigger a while before turning on my pressure washer to bleed the air out when I first connect it. Air in the lines will make it surge.

[Nick Chapman]

Re: Question about pressure washer pumps...

Thanks Tim, I'll give them a call and see what they say.

farmboy, I'll give that a try later today.

Thanks guys!

[Nick Chapman]

Re: Question about pressure washer pumps...

Ok, called the manufacturer, and they had no answers for me

Went out a played with the pressure washer for a couple of minutes again, just to make sure I've tried everything before I made a decision to return the unit. Found out that it only has this problem of surging when the throttle is maxed out. Turn the throttle down a bit, and I get a steady stream of pressure with no surging

Do I have the wrong pump on my machine? Maybe this pump is made for a smaller HP engine, and it can't keep up with a larger HP engine? Or maybe the gravity fed system I have isn't supplying enough water pressure for the engine to run at max RPM's? Hmmmm

[Nick Chapman]

Re: Question about pressure washer pumps...

Hey Nick,

Is your Karcher gas powered or electric?


Tim

Sorry Tim, I just saw this

It is a gas unit. Karcher model # G2401 with a 5.5hp Briggs and Stratton engine....2400psi

[Hemin8r]

Re: Question about pressure washer pumps...

Great question N737NC. I have a gas powered pressure washer (the Craftsman 3.75 hp Gas Pressure Washer Clean and Carry 75200) and was just looking at the water tanks this weekend possibly a 50gal for myself and was wondering the same thing. I want to use it as a gravity fed system but wasn't sure if it would work properly. The guy at the detail supply store said it would. I'll have to check my PW specs as 2hotford mentioned on the min. inlet pressure required.

[Nick Chapman]

Re: Question about pressure washer pumps...

Great question N737NC. I have a gas powered pressure washer (the Craftsman 3.75 hp Gas Pressure Washer Clean and Carry 75200) and was just looking at the water tanks this weekend possibly a 50gal for myself and was wondering the same thing. I want to use it as a gravity fed system but wasn't sure if it would work properly. The guy at the detail supply store said it would. I'll have to check my PW specs as 2hotford mentioned on the min. inlet pressure required.

I don't know how old your pressure washer is. But, just from my recent research, none of the Craftman pressure washers have a pump. You have to supply it with pressured water from the faucet, or buy an inline water pump(I think these are around $100).
Please research your model before you try this gravity fed system thru it. You may ruin it if it requires pressureized water and you run it gravity fed.

[Hemin8r]

Re: Question about pressure washer pumps...

I don't know how old your pressure washer is. But, just from my recent research, none of the Craftman pressure washers have a pump. You have to supply it with pressured water from the faucet, or buy an inline water pump(I think these are around $100).
Please research your model before you try this gravity fed system thru it. You may ruin it if it requires pressureized water and you run it gravity fed.

Thanks for letting me know. I will read up on the specs. I just bought my PW last year so it's not that old. Nonetheless I will read up on it & find out for sure.