# problem with Karcher - pulsing



## DarrylB (Feb 17, 2006)

right, not sure if this is actually or problem or not! recently my karcher has started 'pulsing'. Basically I plug all hoses in and then run the water through to expel any air, then turn the machine on, immediately it starts to make the noise as if it's actually spraying, and it does this every second or so, as soon as you squeeze the handle it sprays just fine, I haven't noticed a drop in pressure in either the water going in or the water coming out. There are no leaks, the tap is on full and it's never done it before in all the time we've had it. 

Don't know the model number off the top of my head  

It's done this twice in a row. Anyone had this before or is this the karcher telling me it's on it's last legs? any help much appreciated :thumb:


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## Georgy (Mar 13, 2007)

THis happened to my old one. I think i tried to sort the seals out as i think its probably due to it loosing pressure. But in the end we chucked it out!


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## ajc2306 (Sep 20, 2006)

I has this problem with a previous Karcher machine. It was the housing on the end of the pump that had cracked. So as soon as there was a slight drop in pressure there would be a pulse from the pump. Unfortunately it was terminal. Must admit though that i still got a fair bit of use out of the machine while it was still doing this.


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## Perry (Apr 22, 2006)

Darryl, mines the same but still works perfect.


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## DarrylB (Feb 17, 2006)

OH FOR THE LOVE OF GOD WHY ME! AAAAHHHH

Fair enough  it's only half buggered then. better get the penny jar ready


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## The Big Yin (Apr 8, 2006)

Mines did it because the o ring on the hose had burst


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## MarkP (Jun 7, 2006)

Happened mine last summer after giving it a lot of abuse cleaning a patio.
Rang my local Karcher agent who said its usually the seals that give up but he asked me the model number, turned out my model was quite old, but better than newer versions as it was made of cast instead of plastic.
I dropped it off to him and £30 later it was as good as new.
He then gave me a tip on how to prevent it.
He said *not* to use those hose connectors that prevent water from passing past them when the hose is unclipped as this can damage the internals.


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## Georgy (Mar 13, 2007)

Get a kranzle machine mate! They are amazing!

I know a Kranzle Rep who may be able to get you some discount


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## Grizzle (Jul 12, 2006)

a seal somewere is goosed in turn leaking water in turn again pressure dropping thats why the pump pulses to keep the pressure up. 

Like said if you can afford it buy a Kranzle.


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## Mini_Nigel (Apr 15, 2006)

The pulsing is caused by the mechanical pressure switch. Open it up and you will see how the linkage works, just reposition the switch a bit so it stays off.


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## SteveO (Nov 2, 2005)

I had this on my Karcher 440 and when it was sent back to Karcher for diagnosis it was down to a blockage in the water inlet pipework inside the machine.

This can happen as the mains water is not always clear of debri fragments. Probably your local water company has been repairing the mains near you and some debri has got into the water supply.


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## DarrylB (Feb 17, 2006)

cheers for all the replies lads! Seems like I'll have to become Dr Darryl for the day and operate on the karcher. It's pretty old anyway and lives in the harsh environment of the shed so I'm surprised it's lasted this long tbh.

Will write a report up of my findings and how the patient is doing, need to get her fit and well again as my AB Foam lance should be on its way over to me.


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## cactusbob (Jul 3, 2006)

My last Karcher started doing this after about 7 years. It started pissing water out of the side too, so I guess a seal had gone. I just bought a new one


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## M.G. (Apr 25, 2007)

I had the same issue with pulsing a few days ago. It turned out that it was caused by the bad seal in the spray lance. It was resolved by my brother in a couple of minutes.  

I certainly would not blame such a little seal to cause it...


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## gtechrob (Sep 11, 2006)

not read all the replies here - ours had pulsing problem - turned out it was air coming in our water supply. try feeding direct from a bucket of water. sorted ours.


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## DarrylB (Feb 17, 2006)

Well...it happend.....

tonight whilst trying out my new AB foam lance, the karcher died on me, it was like loosing a patient at hospital, the pulses got weaker and weaker and then with a final shudder it was no more. only bugger was that i'd only foamed half the car! DOH!

It's a 411 A model which has done us proud! will try and revive it though so all is not lost.

on an up note: how cool is the foam lance!!!! had it on max to start with until I noticed the bottle being drained faster than an alcoholic can knock back a bottle of whiskey!

Lucky my mate has a karcher in the garage so will continue with that tomorrow


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## The Big Yin (Apr 8, 2006)

411a thats the same model as mine quality piece of kit thats done me well for over 6 years


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## gtechrob (Sep 11, 2006)

fyi the smaller consumer karcher's motors are only rated for 15hrs use.


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