Question about Karcher 2500 PSI Pressure Washer

1 Answer

Low Pressure with no hose attached, pressure is good, attach hose without wand and pressure drops 50%. Have had pump apart 10 times, have checked bypass valve, have even removed bypass and filled passage way so water could not bypass wihout any change. Am down to thinking pump casting is cracked allowing bypassing to happen. Does each of the three piston chambers have a check valve so one piston is not pumping back into another piston chamber?

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Karcher Master
  • 1,388 Answers

I worked at a tool rental while attending college and had the opportunity to work on a variety of pressure washers, however, they were of the commercial type. Commercial washers are slightly different in that they usually have seperated components for easier service. Attached to the pump by fittings or rubber hose were the pressure regulator (which has the bypass unloader inside), chemical injector, pressure gauge as well as the hot water release safety all external to pump. Your pump has all these components in one case. By far the most troublesome component is the pressure regulator/unloader which when failing will result in low pressure because it will bypass water back into the intake as you suspect is happening to yours. Here are a few things to check. I believe that your pump is 2500 2.4 gpm. Test gpm water capacity by running pump normally with hose and proper tip attached. Spray water into bucket for one minute and verify that you are pumping 2.4 gallons of water (or what ever gpm your machine is rated). Measure the amount of water that your machine delivered. If it delivered proper gpm and pressure is low then problem could be worn or improper tip. The pressure is created at the tip and pressure will drop as the tip wears. As the unloader/bypass wears, water will bypass at a lower pressure. (Try lowering the pressure regulator all the way ) If water measures less than rated delivery than the machine is bypassing water due to worn regulator/bypass, checkvalves pitted, oring in front of checkvalve worn or cut or missing, or body of pump where checkvalve/oring seat is pitted allowing water to leak past valve. The cap that is removed to access checkvalve must presses against checkvalve with enough force to prevent water from leaking thru oring and body of pump. Examine checkvalves and orings with maginfy lens and look for pitting. Valves surface and orings must be very smooth and tight fitting to work properly. Body of pump where checkvalve oring snuggs against must be very smooth. Any surface where oring seats must be smooth. As water bypasses it cuts metal and orings just like a leaking faucet so look for cuts in metal and rubber. This info and my experience is better suited for larger pumps and higher pressure but maybe it will help. Good luck with your repair.

Posted on Jul 11, 2010

  • kenwats Feb 14, 2011

    Perhaps I do not completely understand the situation, but you said hose attached but no wand. If there is no wand, then I assume you have no nozzle and thus low pressure. As previous responder stated, flow through the tip creates pressure

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Low water pressure from wand


The pressure in a watering wand extension to a garden hose is related to the water pressure from the hose itself.

The point of a watering wand is to provide a gentle and widespread flow of water. If you are looking for a powerful stream, then a different type of attachment is required.

Check to make sure that there is no leaking at the faucet, or at any connecting point. Leaks will lower water pressure at the end point.
Check to be sure the wand itself is free of dirts and clogs. If the wand is dirty or blocked, it will affect the pressure.
If there are several hoses hooked together, the water pressure is more likely to be low at the last point, the wand itself.
When the water pressure drops as a result of another use, like a shower, dishwasher, another hose faucet, then the water pressure will drop in the wand.

Aug 06, 2017 | Water Garden

2 Answers

Engine stalls when not using wand


Frank, either the unloader valve is out of adjustment(try loosening it off) or it is faulty and needs rebuilt or replaced as most people do.
Check the attached vids,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."

Apr 15, 2016 | Honda Black Max 2600 PSI Pressure Washer

1 Answer

Why doesn't it work when the water hose is attached?


Pressure washers can only be started/run with water attached. No water burned out pump in 5 seconds! If pump puts out high pressure water without wand/hose attached, bad wand or hose, if not bad pump. Replace pump.

Apr 05, 2016 | Garden

2 Answers

I have a craftsman pressure washer model 580.752191 no pressure building. checked unloader valve and greased the internal parts, and it does flex (had to do it with channel locks) no pressure


do you get pressure without the hose attached ???
yes ???
bad wand
no ???
stop wasting your time as the pump is most likely bad. Ebay a new one
oh, greasing internal parts can cause them to hang up. 3and1 oil is a better choice, and pump saver should be used when pump is being stored

Apr 14, 2015 | Craftsman Garden

1 Answer

No water output on Task Force 2000 Motor seems


pumps have inlet checkvalves that can be in the closed position that the hose pressure is not good enough for valves to open ther are normally behind hex screw.on pump head

Aug 17, 2013 | Garden

1 Answer

Craftsman Pressure Washer 580.752160 reagent/chemical not being dispensed when wand in low pressure position.


It is very common for the chemical injector valve on these to get gummed up from residual soap sitting in the valve. To clean it follow the chemical hose back to where it attaches to the pump. There will be a hex headed hose barb attached to it. Remove the barb from the pump. Underneath it you will find a spring and a ball bearing. Rinse the parts thoroughly and reassemble. You should also check the chemical strainer that goes into your chemical bucket. They can also become clogged and should periodically be cleaned.

Sincerely,
Aron Kerr
Landa Northwest, Inc.
www.landanw.com

Mar 07, 2011 | Craftsman 2700 Max Psi Pressure Washer 23...

3 Answers

Black and Decker PW1300 Type 1 Pressure Washer The unit will not pressurize, the motor stays on, the water ways seem clear, a low pressure stream (normal for "motor off") comes out when I...


Hi and welcome to FixYa, I am Kelly.
Not sure if anyone has responded to you but.... This is a symptom of the unloader / bypass valve sticking. The unloader bypass valve is located on the output side of the pump either under a brass cap or an extended stem with a knob on it for pressure adjustment.
Try this...
- Lay the unit down so that the water supply connection fitting is facing up. Leave the high pressure hose connected with wand. (Power to the unit)
  • First inspect the inlet screen for debris.
  • Next pour about 3 oz of regular automotive engine oil in the water supply fitting. Take your time... do momentary on / off cycles of the switch (bump the pump.... on / off) You are trying to get oil to the outlet fitting (No more than 1 second on off cycles)
  • Check for evidence of oil at outlet fitting
  • Leave it set overnight with oil in the unit. (Water supply and outlet fittings up.)
NEXT DAY.... add 2 oz more oil and connect water supply. (PURGE HOSE of ALL air before connecting)
  • Do not pull wand trigger yet
  • Cycle unit on and off about 10 times slowly... don't ruin the switch then let sit 10 mins.
  • Turn unit on without triggering and let run for about 2 minutes.
  • NEXT STEP be advised your going to shoot out OIL
  • Begin triggering the wand on 1 sec off 3 seconds for at least 2 minutes (your trying to get the unloader bypass spring / plunger and seals to start moving inside the pump high pressure area.)
  • If your wand has a soap application function make sure the wand is in the HIGH PRESSURE position. (Closed CCW)
This procedure does not always work but, I have revived about 70 % of the pressure washers I worked on by just doing these steps. If the procedure does not work... you will have to disassemble the unloader / bypass valve by pulling it out of the housing and then cleaning up the inside of the pump housing and wiping the seals clean. IMPORTANT STEP here: Before inserting the valve back into the pump housing you MUST lubricate it with #105 white grease. Housing and unloader / bypass valve parts. (white grease in small tubes at any automotive parts source.

Thanks for choosing FixYa,
Kelly

Feb 24, 2011 | Garden

1 Answer

Pressure washer starts then shuts down in 2 seconds


hey mate,

It sounds like your bypass valve/unloader valve is sticking when pressure builds up in the lance,hose and head the pressure cleaner changes to a recirculate mode so it does not blow out hoses or seals or causes any damage to the unit, the bypass valve is the component that activates this sequence if that valve is stuck it will just try to continue to create pressure which in turn puts load on the engine and stalls it...

That is why it starts up straight away and only when it builds up pressure is when the engine stalls.

You would be best taking this to a qualified pressure cleaner technician as there are alot of little parts and orings plus the the head will need cleaning up and the bypass valve lubed, they may not of seen this at the service as it is hard to test a unit without the suited hose and lance... Often use will help this problem when a unit sits for a period of time that will cause issues such as this!!!

Regards
Brad:)

Sep 22, 2009 | Campbell Hausfeld 1800 PSI Electric...

2 Answers

I have a karcher K3.98 pressure washer. The unit surges when I put the wand on and then it stops working. I tried cleaning the wand (didn't make any difference) I then tried another wand from my son's unit...


Dear davedulmage,
To see if the unit is OK....first you must switch it on without water and without high pressure hose and gun. If machinr works smoothly, try by attaching a water supply. Now run the pump with water coming out of the outlet. If also in this case all runs smooth, then attach high pressre hose with gun but without lance. Put on the machine with gun open(to reduce initial resistance) and when you see a clear flow of water coming out...close the gun. The machine should stop. In this case I am suspecting that when you open again the gun the machine will not work. So it seems that when pressure is built in the pump a fault is occuring in the Spill Valve or also called Control Valve. When the gun is closed and pressure built up, this spill valve contracts and switches the pump off. When the gun is opened, the spill valve extends, putting the machine on and closing a valve at the base of the spill valve. So in your case it seems that the spill valve needs to be renewed. A spill valve gets stuck by incorrect using of the pump. For example leaving the pump with pressure in it for a long time. Also it gets stuck by detergents and chemicals. Sometimes I lubricate Spill Valves with high quality silicon grease....but it is much more practical to change it. When a new spill valve is put in....always run the pump with no load. This by usiing the gun without lance or wands, resulting in low pressure. If all OK...add a lance or wand that you are sure it is good. One final thing....to get to this spill valve you must put apart the body and expose the pump. If you are not that good at doing this job...it is better done by a more knowledgeable person. But changing the spill valve is worth it....because it is cheaper than a new machine.
Regards,
Fulltech.

May 19, 2009 | Karcher Garden

Not finding what you are looking for?
Karcher 2500 PSI Pressure Washer Logo

333 people viewed this question

Ask a Question

Usually answered in minutes!

Top Karcher Garden Experts

John Trevino

Level 3 Expert

1388 Answers

Harold Baxter

Level 1 Expert

4 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Are you a Karcher Garden Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...