"Gelf" wrote in message
...
I bought this at the car bootie last year. I guess it's a bit long in
the tooth, but it seems substantially built.
Naturally, it doesn't work properly (always the way!)
The pump runs but the water comes out in rapid pulsating spurts and
the pressure gauge fluctuates from zero to about 1/4 way round.
Any suggestions of likely fault before I strip it down and likelyhood
and source of any spares that may be needed?
TIA Gelf

A pressure washer I used has this same problem, pulsating output.



It was the dump valve (It is supposed to dump the high pressure side back to
the low pressure side when you stop the output) but when you open the output
agin, the valve is supposed to stay shut; it wasn't staying shut due to some
crap in it.



Also, i had the same problem when the lance was partially blocked, the unit
ramped up to too higher pressure, the dump valve operated, the pressure then
dropped as the output was actually open, and then it just cycles like this.
(In my unit, taking off the nozzle at the end resulted in water spraying out
of 4 holes in the side, and one in the end - the one in the end was clogged
with crap, clearing this cleared the fault.



Sparks...