Manitowoc Grove 5540F Service Manual page 70

HYDRAULIC SYSTEM
Table 4-4
Outrigger Circuit Troubleshooting
Problem
No movement all cylinders
Slow movement all outriggers.
Slow movement, one cylinder.
Outrigger lowers but will not raise.
Outrigger cylinder does not hold under
load.
Outriggers only on one side.
Table 4-5
Main Winch Circuit Troubleshooting
Problem
Winch will not lift maximum (rated)
load, considerable reduction in line
speed.
Raise speed is slower than lowering
speed.
Motor will not hold the load when the
control lever is in neutral — load drops
rapidly.
Motor will not hold the load when the
control lever is in neutral — load
drifts down slowly.
Winch does not move.
4-6
Possible Cause
Dirt in relief valve keeping the valve off
the valve seat.
Relief valve setting too low.
Faulty pump section.
Low engine rpm.
Leakage in relief valve.
Internal leakage in the cylinder
Faulty lock valve in base of the cylinder
Leakage in counterbalance valve in
base of cylinder.
Internal leakage in cylinder.
Faulty control valve section.
Faulty selector valve.
Restriction or dirt between the O/R
valve spool and housing.
Possible Cause
Faulty load sense relief valve.
Dirt in load sense relief valve, keeping
the valve off the valve seat.
Not enough oil from the pump.
Improper primary pump pressure.
Malfunction or damage to winch
components.
Internal leakage in the winch motor.
Restriction in hose to control valve.
Faulty counterbalance valve.
Overload condition.
Faulty counterbalance valve.
Overload condition.
Faulty counterbalance valve.
Restriction in holding valve cartridge.
Brake not releasing.
Low pilot pressure.
Published 10-21-2010, Control# 198-04
5540F/YB5515 SERVICE MANUAL
Remedy
Clean the relief valve.
Check and adjust the relief valve
setting.
Overhaul or replace the pump.
Increase engine speed.
Clean or replace the relief valve.
Replace piston seals.
Replace counterbalance valve.
Clean or replace counterbalance
valve.
Replace piston seals.
Repair or replace valve section.
Replace selector valve.
Remove and clean the outrigger valve
spool.
Remedy
Replace the relief valve.
Remove and clean the relief valve.
See Main Relief and Port Relief
Valves.
Check hoses and lines for
restrictions to or from pump.
Check and adjust pressures.
Check and overhaul the winch, if
necessary. See Structurals, Chapter
11. Check for binding or damaged
sheaves.
Replace the winch motor.
Check and repair.
Replace the counterbalance valve.
Decrease the load.
Replace the counterbalance valve.
Decrease the load.
Replace the counterbalance valve.
Clean or replace the holding valve
cartridge.
Check condition of the brake. Repair
is necessary.
Check and adjust.