Hydraulic Powered Pressure Washer
TROUBLE SHOOTING
(Both hydraulic and water systems
)
Symptom
Probable
Cause
Corrective
Action
Pump runs but produces no flow
Pump is not primed
Flood suction line then restart pump. Check the screen
In
the
pump
inlet
hose
fitting.
Nozzle in low PSI mode
Pull or push nozzle into High PSI mode.
Nozzle
plugged
Clean
nozzle.
(see
nozzle-cleaning
brochure)
Pump loses prime
Air leak in suction hose or
Remove suction hose and test for leaks by pressurizing
Chattering noise, pressure fluctuates
inlet fittings
with water. Make sure thread sealant has been used on
all
fittings.
Suction line is blocked,
Inspect it for a loose liner, kinks or debris lodged in
collapsed,
or
too
small hose.
Clogged
suction
strainer
Clean
strainer.
Low pressure at nozzle
Unloader valve is by-passing
Make sure unloader is adjusted properly and by-pass
seat
is
not
leaking.(unloader
valve
adjustment
brochure)
Incorrect
or
worn
nozzle
Make
sure
nozzle is matched to the flow and pressure
of the pump. If the nozzle is worn, replace it.
Restricted
intake
Refer
to
priming
info.
Dirt
in
check
valves
Clean check valves. (see check valve cleaning brochure)
Unit makes knocking noises
Almost always caused by
Check the suction line for kinks, restrictions, clogged
not being able to get
inlet line or strainer, too many elbows, or a reducer
enough
water
at
the
inlet
fitting installed in the line somewhere.
The water suction line is too
A ¾” diameter line is recommended. If the line is
Small for its length
real long, 1” diameter may be needed.
The
water
level
in
the
supply
The
pump should always be below the water level in
tank
is
too
low
the
supply
tank.
The unit makes chattering noise
The unloader valve on the
Try adjusting the unloader valve to reduce its pressure
water pump is unloading
setting. This can also be caused by the vehicle’s
hydraulic system relief valve being set too close to
The
operating
pressure
required
by
the
pressure
Washer. The hydraulic relief valve must be set at
Least
300
PSI
above
the
operating
pressure
of
the
washer. This should be checked with a pressure gauge.
Particles
of
dirt
or
sand
Remove spray tip orifice and clean.
in
the
spray
tip
orifice
Dirt
in
check
valves
Clean check valves. (see check valve cleaning brochure)
Unit doesn’t develop good pressure
Not enough oil getting
Increase vehicle RPM. Check circuit with a hydraulic
to
the
hydraulic
motor
flow
flow
meter to assure that the flow meets minimum
meter
requirements.
Hydraulic
motor
slowing
Vehicle
system pressure relief valve may be set to
or stalling
low. It should be checked with a pressure gauge to
assure that it is set at a high enough pressure.
The
spray
nozzle
orifice
Inspect
this orifice for wear or incorrect sizing and
may
be
wore
out
replace
if
necessary.
