Question about Karcher 2500 PSI Pressure Washer

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Karcher Power Washer Problem

We have a Karcher Power Washer - Gas Unit - M # HD3101DR
Unit will not build up pressure to hose.
1- Clean all filters
2- Clean parts
3- Trying to find the Bypass for this unit. People have said bypass can be the problem, but where is it?


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Re: Karcher Power Washer Problem

I had the same problem with my Karcher. The recall was lifted Aug. 0f 2007. Tried numerous people at Karcher....head of Customer Service, vice president, etc. No one returns telephone calls not even cutomer service....poor, very poor customer service. Thinking about calling Germany.

Posted on Jun 14, 2008

Re: Karcher Power Washer Problem

I can't get the " spill valve" out......any tricks out there that will work?
or just keep trying to pull it out......2400HH :(
email me

Posted on Jun 24, 2008

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Re: Karcher Power Washer Problem

I had same problem won't build pressure. go to and see diagram. I pulled white plastic cover off top of pump (2 torx screws), remove main pump from gas motor otherwise you wont be able to get at the valve below. The important part is the valve below the the white plastic piece, it has a raised slot and mine was stuck in there. I used needle nose pinched together with pliers to lift it straight up. After wd40 and cleaning the hole and valve it should pop in and out easy. Put everything back mine worked like a charm after that. So at least I know what the problem is. Great powerwasher-I use for house painting part time and love it.

Posted on Jun 20, 2008

Re: Karcher Power Washer Problem

Unloader valve is the problem, remove it and grease it with silicone grease

Posted on Jun 02, 2008

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When i switch on the power of my karcher K2.38 power washer, the motor runs but there does not appear to be any increase in pressure, which means that it is ineffective when it comes to cleaning the patio/...

Hi and welcome to FixYa, I am Kelly/
First off, remove the water supply hose from the power washer and locate the in line filter. Most of them are a plastic screen stuffed into the plumbing just behind the hose washer. Others have a short stand off and the filter / screen may be where the stand off attaches to the pressure washer. Others units have in in line sump that usually has a blue or red cap that you remove to clean the sump. Find the filtering mechanism(s) and clean it.
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Should this NOT resolve your problem.... get as much water out if it as you possibly can and pour a few ounces of engine oil into the water inlet. (Easier said than done... but you have to get oil into the pump and then let it sit over night. once you have oil in the pump pull the recoil 2 times with the ignition off just to force oil through the pump)
The next day you go through the same routine as stated above. This brings about 80% of the stubborn ones back to life again. Should it still be fussy after doing all of the above... you will have to replace the unload-er valve. If you removed the un-loader valve for any reason... you must clean out the pump housing and lubricate it and the un-loader valve with white grease (<-Available at any automotive parts source) BEFORE reinserting either the old one or a replacement un-loader valve. If you attempt to use the old one with lubrication.. make sure to remove any debris from the springs and wipe the seals clean with a PAPER towel before lubrication.

Thanks for choosing FixYa,

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I have a pressure washer that runs but no pressure, I was using it at the time and all of a sudden no more pressure.

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If you do get this fixed, we have studied into this and believe the main cause of heads cracking is warm water say if your inlet hose is in the sun for a period of time this can cause the water to become quite hot or if the unit sits and water trapped inside the head assy freezes can also cause this.

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