Karcher Pressure washer surges

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  #1  
Old 06-07-04, 10:58 PM
Azis
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Karcher Pressure washer surges

I am looking at a Karcher pressure washer Model # K 2400 HH w/Honda 5HP. While it does build a bit more presure with the engine running, its apparent when once in a while it surges and produces usable high pressure for a second at best. I have tried different supplies, checked the fittings and filter at the inlet cleaned as sealed. I assume the plastic cap on the end of the pump is a saftey relief valve, it shows no sign of leakage nor does the unit leak anywhere of water whether the wand is triggered or idle. I tried a different hose and wand, although I am not sure it is good either. I searched for online manuals and could find no parts breakdown on the pump. I know enfuff about pumps to know that if four bolts are coming out and all four are under pressure, the pump is not coming apart in the correct manor.
I think there must be a internal pressure relief of some sort when the wand goes idle.
My first pump other than replacements, sure I am in the right place for help.
Thx
Az
 
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  #2  
Old 06-07-04, 11:18 PM
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Hello Azis!

There is an unloader valve that unscrews from the valve body. Remove it and have a look in it. I think it is sticking or broken internally.
 
  #3  
Old 06-08-04, 10:00 AM
Azis
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Thx Cheese,
I have been trying to locate this "Unloader" but see nothing that unscrews from the pump section other than the relief valve. Its held on with two bolts, I removed and inspected it and assume it is like a one time use unit. If not leaking still good???
I dont see any thing else to remove except to seperate the pump sections. The troubleshooting section of the owners manual only says to check lines and fittings then if no luck contact your dealer and mentions nothing of an unloader.
Am I missing it or is this unit buried on this model or..........

Az
 
  #4  
Old 06-08-04, 11:48 PM
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I don't work on enough pumps to know off the top of my head where the unloader is on what pumps...but they are not always externally mounted. It should be very close to the connection to the wand hose. It may be inside the tube going to the wand hose connection. It is usually a ball and seat with a spring...inline between the pump valve body outlet and the wand hose connection.
 
  #5  
Old 06-09-04, 07:59 PM
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re: surges

Hello Azis:

My guess is that your machine has a Honda GC 160 engine and a non-adustable throttle. The "surging" is likely the result of engine governor kicking in.

The sound is frustrating but the engine likely OK.

Good Luck,

Snowman53
 
  #6  
Old 06-10-04, 01:05 AM
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From what I understand from the original post, your engine is not surging...right? It's the pressure that is surging...correct? If the engine is what is surging then it may or may not be the unloader valve...could be other problems.
 
  #7  
Old 06-10-04, 09:57 AM
Azis
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Correct cheese the engine runs fine, it is a honda GC series and it does have an adjustable throttle.
To update this tho, while looking for the unloader, (which I still have not located at least not knowingly) in the outlet I found a plastic insert which I removed to investigate, it screws in on the inside of the output and looks to be a venturi for the soap??? No moving parts only 2 orings on either end, cleaned it and reinstalled. I also began to remove a plate about 1" wide by 3" long that slides, gently tapped it out to see what was under it (this is on top of the brass piece that has the hose in and out fittings?? Valve unit??) After uncovering the first of 3 Round rubber gromet looking...I seen no check ball or springs to unsprung and stopped and returned the plate to where I found it. Could find nothing else on the pump unit itself that looks like it may come off without dissasembling the pump itself.
At this point,(before dragging the washer to and idle area of my shop again) I decided to try one last time, it now works. It does take 3 to 5 seconds after pulling the trigger on the wand (assume this is normal) but then hi pressure comes on and stays on. While I am glad to have it working now, I still would like to know what I may have done for future reference.
Sometimes just getting lucky is better than being good?!?!?

Thx all
Az
 
  #8  
Old 06-10-04, 09:49 PM
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I'm having a hard time picturing exactly what you removed, but it may have been part of the unloader valve, or a cover over it if it is internal. The 3 to 5 second wait for pressure is caused by the unloader. It's still hanging up, but if you can live with that, it won't hurt anything. Maybe it will straighten up.
 
  #9  
Old 06-10-04, 10:47 PM
Azis
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I tried using it again today with mixed results. Now the high pressure will cutout once in a while, and it is slow more like 10 to 20 seconds sometimes to kick in.
What I removed was in the outlet. Looks much like a main jet in a carb except big and teflon or plastic. About 2 to 3 inches long with and o-ring on each end and in the middle it narrows to a jet, it in threads in right where the Valve is for detergent. I had already removed and inspected the check valve for the detergent.
I understand what the unloader does and from listening to the engine when it cuts out its the same as when the wand trigger is released.
I would just like to know I have found the silly thing and either check or replace.
Thx for the help

Az
 
  #10  
Old 06-10-04, 11:55 PM
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http://www.karcher-usa.com/dealers/d.../9139-1060.pdf
the manual would suggest that either you are not getting enough water(3/4 inch hose, 2.5gpm water flow) or the water inlet filter is clogged. This can cause both no pressure, and surging.
 
  #11  
Old 06-11-04, 09:04 AM
Azis
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Thx tae but I have already tried everything that the user manual suggested...
 
  #12  
Old 06-12-04, 02:06 AM
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Can you determine what this part does? Does it move back and forth? I wish I had a diagram of your pump so that I could figure out where the valve is and what it looks like. The unloader valve will allow the pressurized water to recirculate through the pump when the wand trigger is not being used. It should be able to open and close valves or ports to the pump and the wand. They are generally spring loaded. Do you have a digital camera? In the mean-time, I'll check and see if I can find some sort of diagram.
 
  #13  
Old 06-12-04, 11:34 AM
Azis
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I wish the same cheese, if I could locate a parts breakdown I would feel comfortable tearing into it, like I said I started to pull it apart but the 4 bolts holding the brass (valve unit?)on are under pressure so I stopped.
Here is a pic I took of it, I am pretty sure the jet or purple piece I have wired to the outlet,(its wired there cuz that is where it fits once threaded into the outlet) for getting the detergent into the line? The black Cap looking thing Saftey pressure relief? And also in the pic is the flat bar that slides out, under is 3 spring loaded somin or other??? With the jet removed and looking down the inlet I can see a spring on the first one and assume the other 2 are the same...
Anyway I was thinking of putting this pic up so glad u asked for it
http://personalpages.tds.net/~azis/Karcher.jpg

Thx gin

Az
 
  #14  
Old 06-13-04, 08:44 PM
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Ok, this is a link to an exploded view of a Karcher, but not the exact unit you have. It will show you what to look for. Look at figure 2.2, part #5. I believe yours will be very similar. http://www.pressureparts.com/pdfs/Ka...rts%20List.pdf
 
  #15  
Old 06-17-04, 11:09 AM
Azis
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Thx for the research Cheese, the valve body in the diagram is very similar with the exception of the brass plug housing what they call the "Spill Valve". I dont even see an area on my housing that would without a plug that looks like it may house that valve. While looking for that I noticed there is no drain or fill on the pump for oil either...?

http://personalpages.tds.net/~azis/Karcher.jpg
 
  #16  
Old 06-18-04, 01:01 AM
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I failed to mention last time that when I clicked your link to the pic, it didn't work. It does now. It looks like the purple piece you have wired on the pump is not the unloader. I believe you will find the unloader behind where the purple piece is when it is in place. You can remove the valve body if necessary. The springs won't come flying out. They are on the other side of the pump body. Remove it slowly to avoid having them fall out. It's not a very intimidating pump, so don't be afraid to take it off if you need to.
 
  #17  
Old 06-18-04, 10:04 AM
Azis
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Well this has been a fun venture, Cheese I do remember when I had the nozzle insert out I could see a spring looking in the outlet past where the nozzle threads.
At this point the unit is working, it even delivers high pressure now without any delay of pulling the wand trigger. I have talked with the owner and at this point am going to return it without charge along with the info I have aquired including this thread. I will also retain all info as I may see it back in the future. He also has a riding mower that is in need of some front end fabrication he wants me to pick up.
Thx again to all for sticking with this ....
 
  #18  
Old 06-18-04, 11:44 PM
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Ahhhh....the spring was it. (part of it). Anyway, at least it's working now. Maybe the removal and reinstallation of the orfice dislodged something that was causing the unloader to hang up. Glad you got it!
 
  #19  
Old 06-25-04, 07:40 PM
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Thumbs up Delta 2450 with Honda GCV160 CHEESE question

I may be in the wrong place - but...I have the pressure washer described in the title - it appears to be similar to the Karcher you have been discussing. The PDF was great to see. My problem is my engine dies when I let off of the wand trigger. I think it may be the relief valve (spill valve?) you mentioned. The pump assy. on this unit is enclosed and underneath the mount where the motor rests. The engine is vertical shaft and looks basically the same. On the pump there is a hose coming off about 16-18 inches long and capped at the end - this is tie wrapped to another area. What I am looking for is where to locate the spill valve or release valve that might be stuck. I can take photos - but perhaps you have a PDF of a Delta as well ;-) Or any other suggestions. Any help will be greatly appreciated.
 
  #20  
Old 06-26-04, 12:29 AM
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The valve can be shaped different ways and in different places, so it's hard to say just where it is on yours. I do know it will be between the pressure side of the pump and the outlet for the wand, but it may not be so obvious to see. I'll look and see what kind of pump diagram I can find for that model.
 
  #21  
Old 06-26-04, 05:13 AM
calypso
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Unloader Valve

Originally Posted by cheese
The valve can be shaped different ways and in different places, so it's hard to say just where it is on yours. I do know it will be between the pressure side of the pump and the outlet for the wand, but it may not be so obvious to see. I'll look and see what kind of pump diagram I can find for that model.
Dear Cheese (is that BIG Cheese?),
I am going to try and locate the valve this morning. I will take a photo or two. I am assuming you agree that my particular problem is probably the unloader valve. I have read that this seems to be the most problematic item with the consumer grade pressure washers. I have another of the same model for parts - I will get the replacement when I ascertain where it is ;-) Appreciate the help and the site. - calypso
 
  #22  
Old 06-27-04, 01:16 AM
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Would you happen to know what brand pump is on that unit? I haven't had any luck finding a breakdown of that model yet.
 
  #23  
Old 06-27-04, 03:18 PM
intigard
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Karcher power washer

the valve your looking for is under the the BLACK CAP. I just had the same problem. Would have full pressure and then shut off nozzle and then hit nozzle and little pressure. The only way I could get full pressure was to take the tip off , press trigger and then put tip back on. Took the valve off ( hard to get out ) and then put back in, runs fine. Before doing this, one might try filling pump with vingar. I think there was a build up on valve. Here is the parts list everyone was looking for.www.pressure-washer-parts.com/k_2400_parts.asp
 
  #24  
Old 06-27-04, 03:26 PM
Azis
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Wow yep thats the one......Nice Find

Thanks
 
  #25  
Old 07-03-04, 12:10 PM
grb8217
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Intigard -

Sometimes the unloader valve (Under the black cap) get's stuck, the pressure within the pump rises too high and the pump experiences hydraulic lockup (no water gets through the pump) and the overpressure kills the engine. This valve also regulates the output pressure. I have seen other pressure washers with the same pump being run anywhere from 1500-2500 psi. Same pump, just different H/P engines. A Karcher pump parts diagram without the ordering info is at http://www.pressureparts.com/pdfs/Ka...rts%20List.pdf

It irritates me that this information wasn't included with the machine when I bought it but at least there are groups like this to help with finding info. The idea of priming the pump with some white vinegar is good too. It will remove any mineral deposits, just like in coffee makers.

Greg
 
  #26  
Old 07-03-04, 07:38 PM
tigerchief
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Water High Pressure Unit Problems......Pleeeeease help

Borrowed a 1500 psi unit from a friend for a house painting project.....

Hooked it up with no more than a trickle at the high setting and less than garden hose type pressure at low setting....

Checked all the usual manual troubleshooting suggestions with no change in results.....

Called my buddy and asked what the secret was to getting this thing to run right....

He said ....no secret, it ran fine the last time he used it....

He also said he ran it for five minutes in order to make sure it ran before I picked it up.....I asked if this was with a water connection during this 5 minutes?.....he said no..

At this point I was convinced he cooked the pump.....and therefore headed off to Home Depot to pick up a new unit....

Bought a new Excel 6.5 horse Briggs/ 2500 psi unit....

Hooked it up .....and it is performing or not performing exactly as the unit above...

My water supply is a well......with a pump limit switch setting of 40/60 psi

The water coming from the garden hose is easily within the guidelines of the manufacturers min specs of 20 psi / 5 gpm....

Have checked all the obvious .....hose kinks. links, dirt in nozzel, filter, air lock

Any ideas what's going on here????........THANKS
 
  #27  
Old 07-05-04, 12:18 AM
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Very strange that both units are doing the same thing. Sounds like your problem is with the water source instaed of the unit. Did you check to see if you could fill a 5 gal bucket in 1 minute? (5GPM)
 
  #28  
Old 07-05-04, 07:52 AM
tigerchief
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Thanks for the reply cheese.....

Yes, water supply is pumping 5 gals in way under a minute.....water pressure is as good as any town public water pressure....

I'm going to attempt to hook up to a public source later today and see what happens....

Agree, all indications point to my water supply, however I believe it's ok.....
 
  #29  
Old 07-05-04, 10:14 AM
tigerchief
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Hi cheese.....

I measured the gpm rate........my garden hose filled a 5 gallon jug in 32 seconds....
 
  #30  
Old 07-05-04, 10:31 AM
Azis
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What size hose are you using to supply water with? You want volume not pressure delivered to the washer so a bigger diameter hose is better also length of hose, shorter is better....just a maybe and FYI
 
  #31  
Old 07-05-04, 10:32 PM
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5 gallons in 32 seconds is almost twice the volume reccomended. The volume is fine.

Maybe it's a conincidence that both are exhibiting the same problems, and there is actually a problem with each. Do these have different tips that interchange? If so, try a different tip. Maybe it's clogged. I wouldn't think the new one would be clogged though.

Maybe you actually have too much pressure in your supply, making the unloader activate continuously.
 
  #32  
Old 07-06-04, 10:49 AM
Azis
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I agree cheese the supply is sufficient, however was that tested at the hydrant or with the same hose being used on the washer. The main reason I mention this is when I began this thread, I was using 2 25ft lenghts of hose, one 3/8" the other 5/8", I could only get high pressure in 2 or 3 second spurts. I switched to only the 5/8" hose and began to get high pressure after a delay but would continue till I released the trigger on the wand, quite possibly a coincidence but a mental note just the same.
 
  #33  
Old 07-07-04, 01:36 AM
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Good point!
 
  #34  
Old 10-05-04, 12:01 PM
GaryGTAC
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Similar Problem

Well, the previous threads have touched on a problem I've had with my pressure washer. No engine surging, but water pressure surges when operating wand. Have sufficient water pressure and volume, engine idles fine, and I have inspected inlet screen and disassembled wand to inspect. (Eventually I purchased a new wand) I am still having problems and will attempt to investigate the spill valve idea. Further updates will follow.
Thanks,
Gary
 
  #35  
Old 10-05-04, 01:18 PM
JellyFish
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I had the same problem with the output pressure cycling on and off. I had the pump apart 3 times before I finally disassembled the spill valve. It seemed stuck in the body, but I was able to remove it using needle-nose vice grips. I reassembled after cleaning the body and valve. Everything works fine now..
 
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