MDT_im_issue2 © 2023 Page 15 of 16
Problem
Cause
Solution
Pump fails to start
1 Suction hose/tube has a blockage
1 Clear blockage from suction hose/tube
2 Outlet is blocked
2 Check outlet hose and nozzle for blockage
and correct operation
3 Bypass poppet not closing
3 Check bypass valve is closing correctly
4 Vanes sticking
4 Check vanes are sliding freely in the slots
(remove burrs or replace vanes if required)
5 Excessive vane or rotor wear
5 Replace rotor and/or vanes
6 Leak from front o'ring
6 Check o'ring for correct sealing, replace if
required
Pump vibrates but does
not turn
1 Dirt jammed inside the pump
1 Clean pump chamber
2 Faulty motor
2 Replace pump
3 Broken rotor key
3 Replace rotor key
Low flow
1 Blocked strainer
1 Clean or replace strainer
2 Restriction on the inlet or outlet
2 Incorrect size hoses used on inlet or outlet
3 Excessive rotor or vane wear
3 Replace worn or damaged components
4 By pass poppet blocked
4 Check poppet valve for correct operation
5 Low fluid level in tank
5 Fill tank
Motor overheating
1 Fluid to thick (viscous)
1 Fluid to be no thicker than Diesel
2 Motor running longer than 30 minutes 2 Pump must only run for 30 minutes before
cooling
3 Blocked suction hose
3 Clean blockage from suction hose
4 Blocked strainer
4 Clean strainer
Motor not turning on
1 Poor electrical connection
1 Clean terminals and battery clamps
2 Battery low or faulty
2 Check battery
3 Blown or faulty fuse
3 Check pump and or replace fuse
4 Faulty switch
4 Replace switch
Pump leaking out of weep
hole
1 Worn or damaged shaft seal
1 Replace seal
2 Fliud compatibility
2 Only use compatible fluid
Trouble Shooting Guide - all tank pumps