Multiquip LS500 ユーザーズマニュアル

Problem

Possible Problem

To Troubleshoot

Main Hydraulic Pump Noisy

Insufficient oil

Check oil level and for closed suction 
strainer

Air in system

Check for aeration reservoir

Vacuum leak in suction line

Excessive pump wear

Repair or replace

Excessive engine speed

Check for correct engine RPM

Engine bogs down

Low engine speed

Check engine RPM

Main relief cartridge set to low

Adjust relief cartridge

Engine overloaded when pumping

Decrease volume control on main 
pump

Material hose pack

Machine does not deliver volume and 
pressure

Low engine speed

Check engine RPM

Volume control set to low

Adjust control to full open setting

Main hydraulic pressure too low

Check for proper pressure or for 
contaminated relief cartridge

Hydraulic fluid gets hot

Cooling fan

Check fan electrical connection or for 
burnt fan motor.

Fan rotating in wrong direction

Contaminated cooler fins

Clean cooler fins

Return filter element closed

Replace filter

Main relief cartridge contaminated or 
set too low

Replace or set to proper pressure

Hydraulic oil level too low

Fill to proper level

Accumulator gauge reads below 1750 
PSI

Accumulator bottle low on notrogen

Check precharge pressure 1100 PSI

Contaminated safety relief cartridge

Replace cartridge

Defective unloader cartridge electrical 
coil

Replace

Unloader cartridge coil not energizing Check for 12 Volt signal voltage

Defective gear pump

Replace pump

Concrete slurry in lubrication box

Worn or defective urethane cups or 
worn material cylinder

Replace

Material cylinder piston cups squeel

Low on lubrication

Check oil level

Cylinders not completely extended 
(short stroke)

Excessive amount of hydraulic on 
cylinder rod side

Inspect cylinder. Check values for 
contamination or faulty spring

Hydraulic cylinder piston head seal 
leaking

Replace seals