The Stovebolt Site Forums The Shop Area The Tool Chest What makes a pressure washer work?

I just picked up a used pressure washer at a yard sale. It's a DevilBliss exh2425
pump number 0000270183, model 18219 270183. Machine looks like new except for the usual been in storage grime. The motor is a honda gc160 5.0 motor, starts right up and runs like new.

Problem is that the dang thing only puts out slightly more pressure running than it does off. I tried the manufacturer website and found all the manuals and parts diagrams but no useful help when it comes to lack of pressure. I suspect it is just a stuck valve or something.

What makes this thing tick and how do I fix it?

I believe the pump might need some help. Perhaps there is air in the line? When I store mine for a long time, I use a solution in a can that is pressurized and you run in in the pump to keep things clean and lubricated. Also, perhaps there's a restriction in the line or at the handle?

I've never had one of the pumps apart, but believe they are repairable if you have the right parts.

The water flows through the machine with all the pressure the house hose provides. That was my first thought too so I checked it all out and took it apart and blew air through it. There was some hard water deposits in the joints of the wand so I guess I'll be learning what is inside the pump here pretty soon. I took the three plugs and the unloader( #27 ON THIS PDF ) valve out and saw more crusty white crud, but I hate to continue without the rebuild parts on hand.

I have had some trouble with mine after it has been setting for awhile. Last fall I had to take the little valves for each cylinder and and free them up.. The lime in our water caused them to stick. I used it a few weeks ago and it didn't put out the pressure it should have. I am thinking one of the valves is stuck again. They tell me that there is something you can get to put in the pump when it is being stored to prevent this. I think that is what I need to find.
Good luck
Jim

So there are valves in all four of those removable parts on top of the pump? Guess I will dig into all of them tomorrow and see what I see.

One of the problems that causes the lack of pressure problem stems from running the motor without the trigger depressed, not allowing the flow thru the pump. There are different pump types being used on various makes/models and it seems to make a difference. Also well water that has sand or other contaminants can wreck these pumps. I've bought four of them and some only lasted 3 hours. Now I always keep the trigger open even when starting the engine.

I saw that "running the motor without the trigger depressed" comment on the mfg website too, but it didn't tell me what it does to the pump, and how or if it can be fixed. If that is the problem I guess I learned to never buy a used power washer. I bet they don't share that comment with you before you buy the machine either.

Surely the pump can be fixed. If it has built up too much pressure from that, then it has to be a blown seal or gasket which should be replaceable.

Probably a $2 fix, but the mfg isn't forthcoming with the rebuild procedure, and instead, offers a new pump for big buck$.

running with the wand closed for extended periods causes excessive heat build up in the pump due to cavitation

Does that means it pits the internal parts destroying their ability to make a seal? Does that mean the pump is junk?

I took the head assembly all apart and cleaned all the parts I could. I could not get the assembly valves out of the thing, but they turn freely and I can blow air through them one way but not the other. I think that tells me they are working at least. I did not see any evidence of pitting inside the pump except for one tiny spot near one of the pump pistons but it is not in contact with any moving parts so I suspect it is an original factory defect that does not affect operation. I haven't tested it yet, put that off til tomorrow, I'm the camp cook and it is that time of day.

I can't add much, but my Dad catered to the self service car washes in northern CA. The ones you drop your quarters in and grab the wand. The pumps he favored were CAT, and Giant. Probably because they were easy to get parts for. I know that he would occasionally rebuild one, but it wasn't a big part of his business. I wished I had worked with him more knew how to put one together. I know there was a regulator to add soap, but I don't remember if there was any overload protection.

Larry

I got a little bit more pressure but still not working like a pressure washer. Almost perfect for a light car washer but I want to blast something!

Can anybody point me at a "how it works" and how to repair site that goes farther than the first 4 or 5 troubleshooting tips? :mad:

FGT try this site: click

Thanks Wayne, good site with some useful information.

I picked up a used Honda engine power washer last summer. Runs better than my Briggs power washer. It's easier to start power washer engines when the wand trigger is depressed. I also turn the water off and let the pump empty out its water before I shut it off. The Honda will loose its pressure when I release the trigger. If I choke the engine to slow it down with the trigger pulled the pressure comes right back, then I let off the choke. That's the only issue I have with the Honda unit.

What about the square key that couples the engine to the pump? I opened up my honda powered pump and the key was VERY worn - almost to break. If yours is broken, the engine could run without spinning the pump.

Craig

If it has a soap injector on it make sure it is off or it will not have good pressure because it is sucking in air.