MAYCO LS400/LS500 PUMP — OPERATION AND PARTS MANUAL — REV. #6 (09/19/11) — PAGE 63
LS400/LS500 PUMP — TROUBLESHOOTING (PUMP)
TABLE 9. PUMP TROUBLESHOOTING (CONTINUED)
Problem Possible Problem To Troubleshoot
Shuttle Cylinder does not stroke
Incorrect Accumulator System
Pressure
Check the system pressure reading.
Verify it is approx. 1750 PSI
Contaminated Relief Valve
Check the manifold for a
contaminated Relief Valve
Swing Solenoid not energizing
Check for burned out solenoid and
12V signal voltage
Swing Valve not functioning properly
Manually cycle the pump using the
manual cylinder jogging switch
Shuttle Cylinder slow to complete
stroke
Improper Flow Control setting Fully open Flow Control Valve
Incorrect Engine RPM setting
Verify the engine’s high RPM speed is
set to 2550
Incorrect Main Hydraulic System
Operating Pressure
Check the pump pressure gauge.
Verify it is approx. 4400 PSI
Contaminated Swing Relief Cartridge
Check the manifold for contaminated
Swing Relief Cartridge
Low Accumulator System Pressure
Check the accumulator pressure
reading. Verify it is approx. 1750 PSI
Hopper Discharge Nipple Seal
improperly lubricated
Check the Hopper Discharge Nipple
Seal for seizing and lack of lubricant
Misaligned hopper creating excessive
friction on the outlet nipple bearing
sleeve
Realign hopper ensuring S-tube is
rotating in the center of the hopper
outlet.
Lack of lubrication Grease Nun Plate Bushing
Pump Engine will idle but not increase
to full operating speed
Throttle Control Block Solenoid not
energizing
Check for burned out solenoid and
12V signal voltage
Battery voltage falls below 12VDC on
digital display, causing engine not to
start
Blown out fuse Check the fuse
Dead battery Check the charge on the battery
Wiring connection inside Control Box
Check the wiring connections and
verify power is reaching ignition
switch