Outdoor Power Equipment and Small Engines - Northstar pressure washer has no pressure

I recently bought a northstar pressure washer at a government auction for $50. Everything sold there was supposedly working the last time it was used, so I assumed this would work too. I tried it out and the first problem i noticed was water shooting out of the chemical pickup nozzle. I removed the fitting that has the pickup on it and replaced it with a normal fitting, and still no pressure. the water exiting the nozzle is low pressure and the engine won't bear down to pump in high pressure. it is a 3.5 HP and I dont know anything else except the pump does not look like a normal pressure washer pump. It is completely round with the inlet and outlet both coming out the rear of the pump. there is a black knob on the side of the pump which i assume controls the pressure on a unloader valve which appears to be completely enclosed inside the pump housing. I am baffled by this setup, I havent found any pump that look like it online, and I have no idea who makes it. there are no markings on it. PLEASE HELP

For water to "shoot" out of the chemical pick-up tube would indicate that there is a problem with the check valve.
There is a check valve in the soap line or pump that prevents this from happening.

Not sure exactly what system they use in their chemical pick-up circuit but may of them use a wider opening nozzle to allow a higher volume flow to enable a venturi to cause suction, picking up the soap.

Some use interchangeable nozzles to do this and others use an adjustable tip that allows you to open it up to increase the flow and lower the pressure.
Maybe you just need to close down the nozzle.

Is this one like yours?

Click image:
http://www.northerntool.com/images/product/images/157478_lg.gif (http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200329899_200329899)
Image courtesy of: northerntool.com

it is similiar to that, but it is a discontinued model. the one I have has a different style pump. where that model, as well as all the others I have seen have a square shaped pump, this one is totally round. I have no idea who made the pump. I imagine this thing sat for quite a while without being used, and there are probably some stuck valves, I would like to find a diagram before I rip it apart. I wil try to get a picture of the pump to post.

You will find the unloader valve is sticking due to corrosion in the pump. The pump housing is die cast and if any water is left in the pump wall cause corrosion. You are looking at the correct spot for the unloader. The pump is probably from the Italain pump manufacturer or Karcher. If you can get the unloader out of the body, clean it up and look at the "O" rings for cracks. Reinstall with a good silicone grease. I do not know if there is parts still available with out the model number of the pressure washer.

The model number of th pressure washer 157553B, and there were some numbers on the pump. two number on either side of the rear of the pump are 146 and 0020, and a number on the side of the pump is 1460010. Thanks for the help.

I have a parts diagram for the pressure washer that was sent to me by the company, but I am not sure which one of the valves listed is the one that needs to be cleaned up, or how exactly to get to it. I am enclosing a link to the pdf file of the diagram. any help is appreciated.

http://www.freefilehosting.org/public/45186/XB3400rpm%282003%29.pdf

I need some help identifying what is the unloader valve on the diagram from the previous post? Can anyone help?

That's an Annovi Reverberi pump (did I spell that right?). I am not familiar with it, and can't see the passage circuits in it to tell which is the unloader valve. I suggest taking it apart and cleaning/lubing it all anyway.

Yes, it is an AR pump. I guess I don't know what to take apart and what to lube. pumps are kind of new to me.

Your AR pump unloader is items 29 through 33 on the diagram. There is a plastic ball or piston that occasionly will break, but have seen them lood as if they were melted. Otherwise this unloader valve has few problems.

Is MNLINEMAN still around? I think I have the same pressure washer/pump you have and I need to replace a part (looks like a water intake elbow). Unfortunately I can't find the model number in order to order this part. Do you still have that diagram or a model number for this system?