# Karcher K399 pulsing & leaking water internally!



## duckson (Mar 23, 2006)

Guys need some help here.

My Karcher K399 is about 14 months old (purchased March 08) and tonight has developed a fault.
With the hose attached, water on and then the Karcher itself is turned on instead of the pump only activating when the trigger is pressed it is sitting there switching the pump on and off quickly (once a second say), when in use it seems slightly down on pressure and more worrying is that it seems to be leaking water internally from somewhere.

After a bit of googling I've found the espares website and from posts on other forums they seem to lead the fault being either parts 20 or 25, see here:- http://www.espares.co.uk/diagram/pressure-washers/karcher/k3.99m/p/1315/877/14/507562?ed=2800

Has anyone fixed their Karcher pressure washer with symptoms like mine and if so can you point me to the parts you replaced? I may take mine apart to see if i can spot anything thats obviously broken/cracked.

Thanks for any help.


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## pdv40 (Sep 11, 2008)

Had the same issue with mine two months outside of warranty. I took it apart and found part 20/25 had failed. I didn't attempt to replace but instead left it with a Karcher authorised repair agent. After three months of ****ing about I eventually gave up on them and contacted Karcher UK. They sold me a reconditioned K399 for £45 with a full gun & accessory kit as a good will gesture.


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## ChrisD (Mar 7, 2009)

very common fault with the whole karcher range. cant beleieve they are still selling them. But... i now know why there are soo many karcher service stations.


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## duckson (Mar 23, 2006)

*pdv40*, you mean *both* parts 20 and 25 had failed?

*ChrisD*, when you say common fault do you have an idea of the fix, is it a matter of replacing parts 20 and/or 25 as listed above?


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## Ian2k (Apr 13, 2009)

i was going to say ring up Karcher direct and see what they have to say for them selves?


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## duckson (Mar 23, 2006)

Ian2k said:


> i was going to say ring up Karcher direct and see what they have to say for them selves?


Ian, i will do tomorrow before i attempt to fix it / find the fault myself.....this is just a bit of research prior to that. :thumb:


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## little john (Jun 10, 2007)

As its out of warranty they will direct you to a karcher repairer in your area and you will have to pay for the repair, the fault is the pump head part 25 it costs about £15 to buy and the bill for replacement at a repairer comes to about £45 as any more people replace the machine.

This was my PW when it went.





The repairer blamed it on useing a hoselock stop connector.


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## rs200boy (Apr 28, 2009)

ive got the same problem with my karcher too water dribbles out the bottom and it pulses


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## duckson (Mar 23, 2006)

little john, thanks. 
I take it yours was leaking water internally as well (cant quite tell from the youtube clip)? Any ideas if its difficult to replace part 25 yourself?
I am also using a hoselock stop connector at the pressure washer end (ie the type that doesnt allow water out if the supply is on and nothing is attached!)


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## pdv40 (Sep 11, 2008)

duckson said:


> *pdv40*, you mean *both* parts 20 and 25 had failed?
> 
> *ChrisD*, when you say common fault do you have an idea of the fix, is it a matter of replacing parts 20 and/or 25 as listed above?


I don't know which part precisely because I never actually fixed it, but when I took it apart it was leaking a grey goo/grease from this area which suggested to me that something had failed there.

I've been running my replacement K399 for longer now and have had no issues thus far.


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## little john (Jun 10, 2007)

duckson said:


> little john, thanks.
> I take it yours was leaking water internally as well (cant quite tell from the youtube clip)? Any ideas if its difficult to replace part 25 yourself?
> I am also using a hoselock stop connector at the pressure washer end (ie the type that doesnt allow water out if the supply is on and nothing is attached!)


I don't now, I never got that close to it, bu the crack in the head will cause water to leak due to the pressure, the floor was wet as I had been useing it.

as for replaceing it yourself I would thing it can be done if your good takeing suff apart and putting it back together that is.


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## duckson (Mar 23, 2006)

Does anyone know if the screws holdiing it together are the anti tamper Torx head type (ie normal torx head but with a nipple in the middle)?


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## pdv40 (Sep 11, 2008)

I don't think they're anti tamper, if they are they didn't have a problem with me having taken it apart. But my machine was out of warranty anyway.


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## duckson (Mar 23, 2006)

I'm just after whether they are standard torx or anti tamper torx in the Karcher (would of looked last night but it was going dark and i want to pick up some torx or anti tamper torx screwdrivers on the wway home tonight).


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## neilneilorange (Oct 9, 2007)

I'm pretty sure they aren't tamper-proof torx screws. The whole thing to strip down is very easy. Once you get the main yellow cover off, run the pressure washer as normal and you will see where it is leaking. I repaired mine with a two part epoxy (cost £5) and its been fine ever since. 

Other than general stress related wear on that part, frost can also cause damage if left in an un-insulated garage or shed over night. As the water freezes it expands, causing the plastic to split. Make sure you drain it thoroughly (not by operating it without the water running as that will damage the pump) after use if this is the case.


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## duckson (Mar 23, 2006)

neilneilorange said:


> I'm pretty sure they aren't tamper-proof torx screws. The whole thing to strip down is very easy. Once you get the main yellow cover off, run the pressure washer as normal and you will see where it is leaking. I repaired mine with a two part epoxy (cost £5) and its been fine ever since.
> 
> Other than general stress related wear on that part, frost can also cause damage if left in an un-insulated garage or shed over night. As the water freezes it expands, causing the plastic to split. Make sure you drain it thoroughly (not by operating it without the water running as that will damage the pump) after use if this is the case.


Just checked it now i'm at home and the main casing has normal torx, phew. :thumb:
When i've unplugged the water/power i tip the karcher unit forward to pour out any water that might be in the system and also use the gun to try and clear the pipes of water.

Was it part 25 listed here that you fixed? http://www.espares.co.uk/diagram/pressure-washers/karcher/k3.99m/p/1315/877/14/507562?ed=2800


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## Guest (May 13, 2009)

ChrisD said:


> very common fault with the whole karcher range. cant beleieve they are still selling them. But... i now know why there are soo many karcher service stations.


Really? I can't say I have heard a bad word about karcher pressure washers from friends and family, both domestic and commercial machies.


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## Herefordquattro (May 31, 2010)

bit of a resurrection this but rather than start a new thread...

taken my K2.89 apart to try and fix an internal leak seems the 'control head' has a few pinhole cracks in the plastic casing.
Espares want £75 for a new head:doublesho:doublesho:doublesho and considering my wife only paid 90 quid odd for the whole machine 5 years ago i don't think so:wave:

tried patching it up with chemical metal but the leak seems to have moved elsewhere!!:wall: it's quite an intricate shape so difficult to fix.

machine still works but sits in a big puddle and 'hunts' a bit.

Might have to get a new 1 (not this year though) but most annoyingly i've very recently spent £40 on a new high pressure hose and gun for it


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## shaziman (Feb 11, 2010)

Just a small suggestion as this has worked for me for years!

I bought my pressure washer 15 years ago, and it started pulsing 2 months out of warranty. As i wanted to save it from blowing up, when i finished doing the section i was washing, i just turned the unit off electrically. I know many people who have stripped their units down, and tried to repair them, but never either never cured it, or it has lost pressure as a result. Many people have just allowed it to pulse for long periods of time, which obviously has caused more damage.

This has worked for me, and i use it very regularly, and never had any issues. Give it a try, mine still works now!


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