
Aussie BB Hire Series … Operation & Maintenance Manual 9
Aussie Pumps
June 2016
TROUBLE SHOOTING GUIDE
Symptoms Cause Action
No pressure Unloader jammed
Worn unloader valve
Debris in pump valves
Replace unloader valve
Replace unloader valve
Wash out pump , flush manifold and install inlet water
filter, clean valves
Pump runs normally but
pressure is low
Pump is sucking air
Valves worn, dirty or stuck
Unloader seat worn or damaged
Nozzle worn, missing or incorrect
Worn piston packing
Insufficient water supply
Relief valve jammed, plugged or improperly
adjusted
Cracked pistons caused by dry running
Check that hoses and fittings are tight
Replace valves
Replace unloader
Check user manual for correct nozzle size, Check size is
correct, replace if worn
Replace packing
Check supply, clean or replace water filter
Clean, adjust relief valve
Replace pistons
Pressure fluctuates Valves are worn, dirty or stuck
Pump sucking air
Worn piston packings
Replace valves
Check that hoses and fittings are tight
Replace piston packings
Back pressure in supply
hose when on by-pass
Low pressure valves dirty or worn Clean or replace valves
Pulsation Faulty pulsation dampener Check pre-charge, if low recharge or replace
High pressure hose
vibrates
Pump is sucking air from empty detergent
tank
Pump sucking air from hoses or fittings
Air in water circuit
Valves dirty or stuck
Insufficient water supply
Refill the detergent tank
Tighten detergent valve
Check for leaks. Tighten all fittings. Disconnect high
pressure hose and let machine run until water is flowing
constantly without air
Replace valves
Check supply, clean or replace water filter
Machine is noisy Pump sucking air
Valves worn, dirty or stuck
Worn bearings
Water too hot
Check hoses and fittings are tight
Replace valves
Replace bearings
Reduce temperature to below 60ºC
Pump oil is milky
(water in oil)
Worn packings and oil seals
High humidity in air
Sand or dirt entering system
Replace or contact distributor for service
Check and change oil more frequently
Check supply, use only clean water and fit water filter if
required
Water dripping from pump Worn piston packings
O-rings of piston guide or retainer worn
Replace or contact distributor for service
Replace or contact distributor for service
Oil leak
Travel plug in use on pump
Worn oil seals
Oil level too high
Loose drain plug
Replace with breather plug
Replace seals or contact distributor for service
Drain excess oil
Check drain plug fitted correctly
Unloader valve is
‘knocking’ during
operation
Water nozzle partially blocked
Water filter dirty
Clean water nozzle
Clean water filter
Unloader valve is
‘knocking’ when gun is
closed
Gun is leaking
Air in water circuit
Damaged high pressure hose
Faulty unloader valve
Clean inside gun removing any deposits or build-up
See ‘High pressure hose vibrates’, above
Check and replace
Contact Distributor for service
Pressure gauge shows
high pressure fluctuations
when shutting off gun
Valve set too high above operating pressure
Dirty valve
Adjust the unloader to achieve the correct operating
pressure.
Clean valve (removing lime deposits etc, Grease parts
before installing.
Leaky by-pass at nominal
pressure
Nozzle too small, too much water.
Worn out by-pass valve
Replace with correctly sized nozzle
Replace valve
Frequent or premature
failure of packing
Scored, damaged or worn pistons
Overpressure to inlet manifold
Abrasive material in fluid being pumped
Excessive pressure and/or temperature of
fluid being pumped
Over pressure of pump
Running dry … results in cavitation &
cracked pistons
Replace pistons
Reduce inlet pressure
Install proper filtration on pump inlet plumbing
Check pressure & fluid inlet temperature, ensure that are
within specified range
Reduce pressure
Replace pistons, do not run machine without water
These instructions are for trained service technicians, alternatively contact your nearest Aussie service centre.