Mec Speed Level 2684 RT Service And Parts Manual page 174

LIFT AND DRIVE
No drive or lift Main Relief Valve RV-3 out of adjustment
operation motor
operates
Pump or pump coupler failure
Diverter Valve EC-1 malfunction
Hydraulic tank empty
No drive or lift Motor malfunction
operation motor does
not operate
System interlock
Battery discharged
STEER
No steer in either Joystick rocker switch inoperative
direction
Steering Valve SV-2 inoperative
System interlock
Hoses connected incorrectly
Pressure Relief Valve RV-2 set too low
Steers in one direction Steering Valve inoperative or stuck
only
No power to steering coil
System interlock
Steers but not fully or One or both steering cylinder internal seal
steers slowly failure
Pressure relief valve set too low
King pin/s seizing in the bore
Wheels do not stay in One or both steering cylinder internal seal
position while driving failure
Steers uncommanded Steering Valve SV-2 sticking or damaged
Check Valve CV-1 or CV-2 damaged or
contaminated with debris
LEVEL, AUTO & MANUAL
No level operation Platform is in elevated position or is
perceived to be in the elevated position.
Elevation is monitored by a sensor located
on left-rear portion of the scissor stack.
System interlock
Level switch/s inoperative
Directional pressure valve not functioning
November 2009
Page 4b-32
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R O U B L E S H O O T I N G
"3084 Speed Level™ Sigma Lift" Service and Parts Manual
- - T
M O D E L R O U B L E S H O O T I N G
For test purposes, swap RV-3 with RV-2.
Inspect, replace as necessary
Inspect, replace as necessary
Check, fill with approved oil
Inspect, replace as necessary
Check HELP messages using EZ-Cal
Will receive 4-4 or 7-7 flash on GP400. Clean, service and
charge batteries. Battery charger may not operate if battery
voltage drops below 20 volts.
Check rocker switch output on green and yellow wires, input
on blue wire.
Check steering valve for power or damage.
Check HELP messages using EZ-Cal
See hydraulic section for correct connection.
Set steer relief valve to 2000 PSI
Inspect; replace steering valve
Check for power and ground in both directions, repair wiring
Check HELP messages using EZ-Cal
Check steering cylinder seals, replace
Set steer relief valve to 2000 PSI
Disassemble and inspect, repair, replace bushings
Check steering cylinder seals, replace
Remove and inspect for visible debris and stem
straightness, clean with solvent and air
Remove and clean or replace check valves see hydraulic
diagram for manifold location
Use EZ-Cal to monitor platform state of elevation. See
Diagnostic chart I.D. 2a13 for elevated status and 2e1 for
platform % of elevation input. Failure of the angle transducer
will trigger a fault code.
Check HELP messages using EZ-Cal
Check level switch located in the upper control box
Located behind lower control box. Inspect valve for loss of
power, ground or damage.
C
H A R T