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Karcher pressure washer

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BOB BLACKSHAW09/08/2019 10:25:51
192 forum posts
35 photos

My Karcher pressure washer which is around 25 years old gave up this week.

The problem is that the motor is working but is not pushing out the pressure, it was working fine on the job I was doing then gave up.

When the motor is pumping it now pushes out slightly more than when on mains water pressure

Is this a simple fix or time to buy a new one, its not had a lot of use over the years still in the original box.

Thanks Bob.

Howard Lewis09/08/2019 10:59:57
2212 forum posts
2 photos

If the motor is running, it sounds like the problem could be.

Loss of drive to the pump. or Pump failure. (possibly stuck parts die to prolonged lack of use )

This may be no more than the vanes have stuck, if a rotary pump.

If a reciprocating pump, it may be that the piston rings have stuck / corroded.

Could be no more than sticking valve/s

Hopefully, freeing off the stuck parts will not be too difficult, and it will be restored to actiuon.

Howard

 

Edited By Howard Lewis on 09/08/2019 11:00:43

Barrie Lever09/08/2019 11:02:09
323 forum posts
1 photos
Posted by BOB BLACKSHAW on 09/08/2019 10:25:51:

My Karcher pressure washer which is around 25 years old gave up this week.

The problem is that the motor is working but is not pushing out the pressure, it was working fine on the job I was doing then gave up.

When the motor is pumping it now pushes out slightly more than when on mains water pressure

Is this a simple fix or time to buy a new one, its not had a lot of use over the years still in the original box.

Thanks Bob.

Bob

I had the same with a Karcher jet wash of similar vintage, it is to do with a pressure switch if I remember correctly.

Run it with the cover off and you might see the device, I managed to coax mine back into life and it is still running OK 15 years after, it is something to do with how the washer handles the low pressure requirement when using a hose brush and then switching to the high pressure mode with the nozzle fitted.

Barrie

Bazyle09/08/2019 11:17:49
avatar
4686 forum posts
186 photos

Beware if disassembling the pump that it is full of oil.

Joseph Noci 109/08/2019 12:04:23
536 forum posts
832 photos

I have a large one, diesel fired to heat the water as well, when desired. It does (rather, 'did' ) not get much use, and that caused the problem. On mine the pump has 4 pistons affixed to a swashplate that the motor turns directly. That whole assembly is in oil. The pistons pass through a wall to the water side of things, with a rubber seal on both sides of the wall, one in oil, one in water then into ceramic pressure cylinders. When the pump stands for weeks, the water dries out in the chamber ( runs out, dries out, etc) and the next start the pistons run dry in the water jacket side rubber seal for a short while, and the seal wears out much sooner. Then the water is simply moved around inside the water chamber, from cylinder to cylinder, and nought exits the pressure valve - hard to explain the exact geometry, but sound seals are the key..

The vendors sells a kit which includes pistons, all seals, some 'O' rings, etc and it took maybe an hour to make like new. Now I use the machine much more often...

Joe

Edited By Joseph Noci 1 on 09/08/2019 12:04:37

not done it yet09/08/2019 12:05:02
3246 forum posts
11 photos

Mine gave up recently. The two of the three non-return valves were jammed open. There were lumps of dried scale, which had presumably slowly grown bigger over the years.

Carefully cleaned them out (the valves are fairly frail) with a pick and away it went. New valves are not too expensive and I think many pressure washers are discarded rather than being repaired. Plastic pumping heads are likely less worthy of repair - so much for the throw-away society of the present day!

The older pumping heads were far better than those on most modern cheap sets. They will likely withstand hot water . Mine has a metal pumping head - most are plastic these days.

Usual precursor to valve failure is that the pump restarts too regularly - the pressure switch holds it off at full pressure, but back-leakage causes regular motor restarts - not so good for a capacitor motor when every few seconds. Eventually the valves just don’t even allow pressure to be attained.

Bazyle is right with his warning. Keep it vertical (upside down) when removing the pumping head!

Soaking in warm/hot citric acid solution may be enough to dissolve the lumps, or at least a preventative maintenance job at regular intervals, if located in a hard water area.

BOB BLACKSHAW09/08/2019 14:47:37
192 forum posts
35 photos

Thanks for the replies,

I will have a look this weekend and see what's going on.

I was suppressed how cheap they are to buy new, easy to become a throw away society member.

Bob.

Nick Clarke 309/08/2019 20:45:04
avatar
359 forum posts
9 photos

Mine doesn't get used much (just look at the state of my car for confirmation!) but if it does not spray splitting the Lance in two and using the pricker on the jet itself will usually bring it back to life.

Just a suggestion before you get too far into the entrails if your machine.

not done it yet09/08/2019 21:06:00
3246 forum posts
11 photos
Posted by Nick Clarke 3 on 09/08/2019 20:45:04:

Mine doesn't get used much (just look at the state of my car for confirmation!) but if it does not spray splitting the Lance in two and using the pricker on the jet itself will usually bring it back to life.

Just a suggestion before you get too far into the entrails if your machine.

That will show the following signs (or is it symptoms?).

Motor will start initially to raise the pressure. Motor should then stop on the pressure switch and fail to restart for some time (dependent on the state of the valves).

Not the same as the OP is experiencing.

Mike Poole09/08/2019 23:48:01
avatar
2045 forum posts
47 photos

I bought a pressure washer when I got a car with alloy wheels, the novelty soon wore off and now I have a car with dirty alloys occasionally cleaned by our hard working car washers from the EU.

Mike

Kiwi Bloke10/08/2019 03:24:56
227 forum posts
1 photos

It should be an easy fix. My >30-year-old Karcher HD 575 is still going strong, but has always had a problem where pulling the trigger doesn't always release more than mains-pressure water. Usually, after a few trigger-pulls, or a bit of a wait, it is fine, only to 'fail' the next time the trigger is released. Or not... Annoying. Due, I'm sure, to it not being used enough, so evaporation of the water inside leaves the solids to gum up the works. The cure is to remove, dismantle and clean the pressure-adjusting valve. A smear of silicone grease helps. Similar attention to non-return valves, as above (NDIY), might also be necessary. The pump also piddles water out from the pump body drain orifices. This is because the piston seals wear. It's all an easy fix - assuming spares are available (here, in NZ, I'm not hopeful).

The pump is easily dismantled, without worrying about oil, orientation, etc. The swashplate assembly, between pump and motor, is oil-filled, but does not have to be disturbed for pump maintenance.

Repair, don't replace!

pgk pgk10/08/2019 06:51:13
1425 forum posts
278 photos
Posted by not done it yet on 09/08/2019 21:06:00:

That will show the following signs (or is it symptoms?).

Signs = what is observed

Symptoms = what the patent feels (subjective)

I'm retired, I should keep my mouth shut...

pgk

not done it yet10/08/2019 07:48:36
3246 forum posts
11 photos
Posted by pgk pgk on 10/08/2019 06:51:13:
Posted by not done it yet on 09/08/2019 21:06:00:

That will show the following signs (or is it symptoms?).

Signs = what is observed

Symptoms = what the patent feels (subjective)

I'm retired, I should keep my mouth shut...

pgk

I know. They were definitely signs to the owner, but are they then symptoms when the owner posts them on here?! smiley

Clive Hartland10/08/2019 08:14:16
avatar
2463 forum posts
40 photos

One aspect about power washers is that when used and put away they are left overwinter in a side shed. It freezes and the freezing water damages the pump.

Next door had this happen, as they are cheap he threw it away.

pgk pgk10/08/2019 08:32:29
1425 forum posts
278 photos
Posted by not done it yet on 10/08/2019 07:48:36:

I know. They were definitely signs to the owner, but are they then symptoms when the owner posts them on here?! smiley

Yeah... but that would be his symptoms (sadness, ennui, financial anguish...) not the washer's laugh. But doubtless a case for compensation from kaarcher for the mental distress, especialy if he can claim to be a minority such as an investment banker with too much money and a coke habit.

Joseph Noci 110/08/2019 09:04:58
536 forum posts
832 photos

And there the Forum Falls Foul of Flexiloquent Folk partaking in a Floccinaucinihilipilification process....

Joe

pgk pgk10/08/2019 09:49:08
1425 forum posts
278 photos
Posted by Joseph Noci 1 on 10/08/2019 09:04:58:

And there the Forum Falls Foul of Flexiloquent Folk partaking in a Floccinaucinihilipilification process....

Joe

Serendipitous and beats the phrase I found last week of "Pucillanimous and pestiferous paltroonery' (which I'm still trying to slip into a pub conversation)

Kiwi Bloke10/08/2019 10:01:17
227 forum posts
1 photos

'And there the Forum Falls Foul of Flexiloquent Folk partaking in a Floccinaucinihilipilification process...."

Our grandiloquent friend is surely mistaken: there was no ambiguity nor worthlessness opined. Pedantry perhaps, but correct usage of vocabulary seems to be a vanishing ability.

Ian S C10/08/2019 11:37:09
avatar
7444 forum posts
230 photos

Not sure where you are Kiwi Bloke , but there are Karcher outlets in Auckland, Hamilton, Wellington, and Christchurch.

Ian S C

Joseph Noci 110/08/2019 12:45:23
536 forum posts
832 photos
Posted by Kiwi Bloke on 10/08/2019 10:01:17:

'And there the Forum Falls Foul of Flexiloquent Folk partaking in a Floccinaucinihilipilification process...."

Our grandiloquent friend is surely mistaken: there was no ambiguity nor worthlessness opined. Pedantry perhaps, but correct usage of vocabulary seems to be a vanishing ability.

I was wondering where the worth was in :

I know. They were definitely signs to the owner, but are they then symptoms when the owner posts them on here?! smiley

Yeah... but that would be his symptoms (sadness, ennui, financial anguish...) not the washer's laugh. But doubtless a case for compensation from kaarcher for the mental distress, especialy if he can claim to be a minority such as an investment banker with too much money and a coke habit.

And the various bits of similar ilk, to the chap trying to find some help with his pressure washer...So , yes, rather worthless...and the vocab seems quite apt.

Joe

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