Multiquip LS400, LS500 manual Psi

LS400/LS500 PUMP — TROUBLESHOOTING (PUMP)

TABLE 9. PUMP TROUBLESHOOTING (CONTINUED)

Problem	Possible Problem	To Troubleshoot
	Insufficient oil	Check oil level and for closed suction
		strainer
Main Hydraulic Pump Noisy	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
	Low engine speed	Check engine RPM
	Main relief cartridge set to low	Adjust relief cartridge
Engine bogs down		Decrease volume control on main
	Engine overloaded when pumping	pump
		Material hose pack
	Low engine speed	Check engine RPM
Machine does not deliver volume and	Volume control set to low	Adjust control to full open setting
pressure	Main hydraulic pressure too low	Check for proper pressure or for
		contaminated relief cartridge
		Check fan electrical connection or for
	Cooling fan	burnt fan motor.
		Fan rotating in wrong direction
Hydraulic fluid gets hot	Contaminated cooler fins	Clean cooler fins
	Return filter element closed	Replace filter
	Main relief cartridge contaminated or	Replace or set to proper pressure
	set too low
	Hydraulic oil level too low	Fill to proper level
	Accumulator bottle low on notrogen	Check precharge pressure 1100 PSI
	Contaminated safety relief cartridge	Replace cartridge
Accumulator gauge reads below 1750	Defective unloader cartridge electrical	Replace
PSI	coil
	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	Replace
	worn material cylinder
Material cylinder piston cups squeel	Low on lubrication	Check oil level
	Excessive amount of hydraulic on	Inspect cylinder. Check values for
Cylinders not completely extended	cylinder rod side	contamination or faulty spring
(short stroke)	Hydraulic cylinder piston head seal	Replace seals
	leaking

PAGE 64 — MAYCO LS400/LS500 PUMP — OPERATION AND PARTS MANUAL — REV. #6 (09/19/11)