Flushed with success after fixing my cheapo drill I turned
my attention to my jet washer.
This time it’s a quality German product - a
Kärcher 475. I think that a jet washer is essential if you're going to ride a bike
through the Scottish winter. It's great for blasting off dirt and road salt. I
bought mine a long time ago but recently its lost its mojo. It was just about
ok for cleaning the bike but when I tried to clean the patio I realised that
its pressure was well down. The gauge showed 40 bar instead of the usual 90 bar.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDfK8r8KeiKPpVIS12Z4ZOk9Rrquc6tip57a_Ddp9QxLu9a_A2cO3rfAtmOkPhiTCvUPH_ePK2FzUq8GG-e103E_9Z6huSH3hXZ08W55F9TcoQrYn3fqSuzSK4LLDHbBoojKYZN7hbenpk/s400/b%252301.jpg) |
The gauge told me something was wrong |
A pressure washer is just an electrical motor at one end and
a pump at the other. The motor seemed to be running ok so I though I'd take a
look at the pump. Now I don't really know how this works but, hey, that never
stopped me before.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5eO9HCrwwhWCyUJ97_WhbdQpjKJfQC4Xh-s7e0tam03Qh-2SC8TTqxisVunV40XkP_Xty3GhaPPaQ0WNQoOzdK33-l4iPlvYsqLdOL9JENogICGpYaDBcPIO87_PwQZsEfIG-WJeAd0bO/s400/b%252302.jpg) |
I didn't need to open up the electrics but when I did
there was a wiring diagram inside. Nice. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikwsX2BmRHoaNwHGXl9j73c3HWb-1Y5O0DpYd42Y1GfAGcbgTw3UnI9KexxuzbWjLkFh9z8xNjFximSVIY0iVRZAvkVhSIjhn51IYw8lJUSj6EQIjEVIZRDeVhzScDxP9jLuG4iajOoR8f/s400/b%252303.jpg) |
This sticker shows that the machine was made in 1990, so it
has given me a lot of years of service. It also tells me that cos φ, the power
factor, is 0.95….those Germans! |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUg9Qj68ySNH8CmHlOqR-IY0GAf84_DqkEDhCW9ecbOsYVOfWoOkPRTpDeqamtvegrMUyEWgoe_jjDLTmcWPoSanBzQb95bL9HMG_7o9NYAjCNKjQ_NHPe-Sq9OA2U8KXG-53Txxc1T9LZ/s400/b%252304.jpg) |
These pistons go in and out…. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVLoZUgciO9ZTQOqwIk67VbxfJKGF5Jpc-vaB6yA9tV3BaqaF-c1uMajDFyLieIZMhkl60-0LpZCYEJ_hA5x2gdfM2K186F-h9EBgL6EsQ6bTiND7bjw9UpPfMwY4W1Y30o6zl87-L35jp/s400/b%252305.jpg) |
…into these pump units. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLNbXpg1fHmi56I1zwSa-2bpx1lw1t2i0PeFRXS6Go7FGjFNb4y3kkDFhEeo_UvAsKi-Npc7jdMs_d59VGvys65aH6zrlpt05uX4cf8pX6HsuOTk7DIJC99subdlANE_8phMppMMLx_iD8/s400/b%252307.jpg) |
The pump outputs. There's something funny going on…..a
broken O ring is jamming one valve open.
|
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZrNv0NJC1LY9d6Lkj-LU2VHJHP_oH-rgaIpPpKG-HbsTDTXNwkgIsflSyZlkvs9tHqRbwVFfsn687bhQ4y9Z2cs0bHn4G2PNVDLUNNu9VOUAQobH9wglyuddH4u6ETSk6A61aJ3agdt45/s400/b%252308.jpg) |
O ring |
It wasn't obvious where the O ring came from. There didn't seem
any way to further disassemble things so I cleaned it up and put it back together. And it worked fine. Back to 90 bar.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiW_yRpSqGmpe_cYhA9J3cddhpblJF5Q554FHgGH_OU_zkznP7aVMQfGAyiawhqpA7JcSP2fueZ2FhtaeXLPAR0HTpxFiI4hz44WI6CYeeM5t2EsnbgMQcP4rbXA1Ahyphenhyphenc3zsgNj0bhK1NSw/s400/b%252309.jpg) |
Back to its patio cleaning best! |
So where did the O ring come from? Because the washer is now working fine I didn't think it came from inside. Looking about I found a self closing connection of a type I used in the past and that has an O ring that looks similar. The washer is suppose to have a mesh filter on the inlet but I removed this for some reason years ago. So mea culpa (as usual)
Now where did I put that filter?......