Kew Pressure Washer problem ... update

I previously posted that I have a KEW Hobby pressure washer ...... been
great to date ..that had started surging.
No shortage of incoming mains (pressure or flow rate) even tried different
hoses & fittings to be 100% sure of that.
OK - as hose was crumbling away, .... bought a new hose, incl hose fitting
.... so can now discount the hose, lance & nozzle from being the issue.
Loads of water through lance if trigger operated (motor off)
When motor is on ... when lance operated it is surging ... aprox 2 sec full
pressure 1 sec low pressure.
Now previously it was mentioned that when I release trigger .. pump still
runs, and it uses a bypass valve to release the pressure .. and this could
be at fault.
Anybody know what this would look like, and is this something worth
stripping & perhaps cleaning.
Last option I suppose would be if there is somewhere that services KEW.
Like many British Manufacturing companies - they are no more.
Reply to
Rick Hughes
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Very likely it is. The valve is opening too soon by the sound of it.
On an old KEW hobby it was probably adjustable - which KEW hobby do you have - is there a model number?
KEW were Danish :-(
Started by a Knud Ernst Westergard who worked for Gerni in Randers, Denmark, now defunct, but once part of the Nilfisk group.
Bought by an investment group - renamed Alto, then bought by Nilfisk - they now trade as Nilfisk-Alto.
Dozens of places will repair them. Worth hanging on to, it was the last of the quality hobby machines.
Reply to
The Medway Handyman
I made the 'mistake' of lending mine (Kew Hobby, the shape and weight of an arc welder) to a pretty good friend but with the strict reminder that 'I don't normally lend stuff out to anyone' and to 'make sure you look after it'.
He took a long time returning it and eventually I found out why. He had be using it to clean the loose stuff off his house after we had replaced all his windows with new uPVC jobbies and because it was a nice day and his kids were outside he was mucking about spraying them with it. In an effort to run away, one tripped over the mains lead and ripped the cable clamp and part of the case out.
Although quite old even at that point it (had) looked like new (it was 'mine') and of course parts were either difficult to get or very expensive. Luckily it still worked as such but ...
How does it go .. 'Neither a borrower nor a lender be.'
As my Dad used to say re this sort of thing ... 'You have nothing to gain and everything to lose' and generally he seems to have been right. [1]
Cheers, T i m
[1] The only rider with that is if I do lend it to you and you break it you buy it ... or buy me a same > better replacement one ..'. With some people that goes unsaid but others ... ;-(
Reply to
T i m
Yes .. Hobby 88
I passed the KEW factory once at Penrith, assumed they were British.
yep .. that is why I want to fix it, seems so much better built than the plasticky Karchers
Reply to
Rick Hughes
Can't find an online manual for that, but the unloader/by pass valve will be built into the pump head & have a screw to adjust it.
Do you have a photo of the pump head you could post? I could prolly spot the unloader screw.
Thats where Nilfisk Alto are now, same building.
Reply to
The Medway Handyman
down by 4 hex head bolts. It could well be under the pressure gauge, so look their first.
What you are looking for is a screw that compresses a spring. It needs tightening.
What should happen is; when the gun is shut the pressure rises, forcing a valve to open against the spring and the water returns to the inlet. So if the working pressure of the machine is 100 bar, the spring will be under enough tension to hold the valve closed at 100 bar, but will allow it to open at 105 bar.
Whats happening to your machine is; the spring is broken or out of kilter it might be allowing the valve to open at 80 bar. So pressure rises to 80, valve opens, pressure drops to 0, valve closes, pressure rises to 80 etc etc.
Reply to
The Medway Handyman
On Jul 4, 8:07=A0pm, The Medway Handyman wrote:
OK .. take a look on weekend ... thanks
If anyone else is familiar with Kew feel free to chip in
Reply to
Dave (or others) ... OK .. to me it looks like it would vent out water via the plastic tube marked 'X' in the pic 1:
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the brass casting ... there seems to be some form of screw in plastic pieces (strainers?) or of which does not look good ... Marked 'P' in pic 2
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rings were actually crunched - so had never been installed correctly. Does this aluminium casting look OK .. the hole to the right of where I marked the 'P' looks corroded.
The Brass casting has a large hex nut
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... and inside of which is a slot headed screw
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either of these look familiar to you as 'unloader valve.
I found the comment below on line ........
A pressure washer unloader valve prevents the pressure from building to the breaking point when you aren't spraying water. A "diversion loop" is created to cycle the water back to the inlet valve and inlet part of the water pump. Unfortunately, the unloader valve is often a cause of trouble. Some power washer users report problems such as the pressure washer motor dying after spraying is done, minimal pressure, and sometimes even leaking sprayers. There are a variety of fixes to problems such as these, the simplest being the replacement of the unloader valve. If you need to do this kind of pressure washer repair, it's absolutely essential to replace the power washer valve with one that has equal or better gallons per minute (GPM) and PSI ratings. Failure to do this can result in additional pressure washer problems, including a safety hazard connected with the pressure of the unit overwhelming the unloader valve, compromising or even destroying it.
Reply to
Rick Hughes
suspect that tube is the inlet to the pump from the jacket. Thats where any 'unloaded' water would return to.
Doesn't look too bad, should last a while.
That looks exactly like the unloader valve adjuster.
Try turning the screw clockwise & see if it helps. Half a turn at a time, don't go mad.
If no good, strip it out & see if the spring is broken.
That has to be American. Power washers are very different in the USA & primitive compared to the European ones - mainly due to the Micky Mouse US electrical system.
That refers to a separate bolt on unloader. Our machines have them built in to the pump head.
Reply to
The Medway Handyman
The plastic screw in 'things' ... look like some form of strainer, do you know if these are available as spares ?
Reply to
Rick Hughes
Tried them they pointed me to PressureClean UK ... who say ... no parts available for Hobby 88
So everyone seems to suggest its a quality machine .... but seem to strike out on parts.
Anybody any other suggestions ?
Reply to
Rick Hughes
As I said, its an oldie but a goodie.
I suspect either adjustment or a new spring is required. You might be able to pick up a suitable spring from
Reply to
The Medway Handyman
Thought I'd give an update in case it helps others.
The company that bought out KEW ... Nilfisk-Alko carry no spares at all for Kew. Apart from hoses & lances, nobody seems to stock parts for Kew ....a pity as it seems a substantially built machine ... large stainless steel water-cooled motor, multi-stage pump, rugged brass castings.
In my case the 'surging' was assumed to be the unloader valve, tripping at too early a pressure.
The screw head slot visible in picture ... did 'not' adjust the spring pressure, as it turns freely ............ you would have to insert a socket at other end of shaft to hold the nyloc nut while you turned the screwdriver ......... I didn't find that out until I stripped the valve.
The very large brass nut in the picture was undone ...and it took a huge amount of torque to get it out (and a big Stilsons) this then unscrews the unloader valve.
Once out I checked spring .. all seemed OK, I physically rotated the 'poppet' valve on it's seat, it sound a bit crunchy initially then OK ... could se nothing wrong ...... so reassembled .... and it is now working fine.
SWMB is now out using patio scrubber attachment and doing all the patio & paths (she enjoys it)
So it was the valve (thnx to those who explained how it worked) ... assume something was stuck or there was crud somewhere.
Reply to
Rick Hughes
Hi happened to read half this thread (cuz I have one 2 days ago) as I had t= ried my cheapo plastic washer using my hobby hose. It stripped the threads = as it blew the hose off! I tried it back on the Hobby and same deal - blew = it off! The retaining plastic 'cap' was split and after much messing with j= ubilee clips I forced a 15mm water pipe union over the hose flange having f= ile them both elliptical (worked) and found I had the same problem I was re= ading about. So here I am and really appreciate this thread. I will remove = that big nut asap as I got the idea that the screw is not the adjuster as e= xpected-right? or as it just loose? I have not used it for years and I reca= ll baulking at the price of zinc oil even then. I have white creamy oil in = there. Was the zoil red? Is it critical that I use zoil? Is an Hypoid gear = oil okay? I think I had grit in the nozzle and having removed a 'u' shaped = clip I removed it and it was better than my first initial jets. Whilst spit= ting it occasionally issued creamy water! Is that my oil contaminated and a= suspect o ring? Nice to meet you all and I look forward to your answer. Thanks
Reply to
alan darn
Hi, I had it apart. I gave the screw a quarter turn. It was fairly stiff. I= think it may have resulted in jet even more 'on'. Came back hoping for mor= e info regarding screw. Brass screw is too stiff unless I find a way to rem= ove the oil fill tube for clearance. I gave it a fair bit of antiCW torque = but didn't want to crush it. Chrs. Anybody?
Reply to
Z Fell
Took it all apart. Gave valve some manual compression as mentioned. Assembled...still pulses. Stretched spring to increase tension.....still pulsing. I may stretch further - weather permitting. Lonely in here.
Reply to
Z Fell

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