Mec Speed Level Series Service & Parts Manual page 122

Secton 8 - Troubleshootng - 3084RT Models
Problem
Maintenance lock in maintenance position
Lowering valve not energized
Platform will
not lower or Lowering valve not shifting
lowers slowly
Lowering orifice/s plugged
System interruption
Lowers but
Down valve on lift cylinder inoperative
not completely
Lowering valve not shifting
Emergency
Lowering orifice plugged
lowering not
E-down battery discharged
working
Valve coil failed on cylinder
Drive
Lift/Drive select switch not in Drive position
or not operational
Drive valve not shifting (SVD1)
No drive
function
Proportional Valve not shifting (SP1)
Drive system shut down (interlock)
Unit out of level
No drive
elevated
System Interruption (interlock)
High torque enabled
Slow drive
with platform Malfunctioning rear wheel bypass valve
stowed
Wheel motors not functioning correctly
High or mid speed enabled
Batteries discharged
Wheel motors not functioning correctly
Poor
gradeability
Malfunctioning rear wheel bypass valve
or drive
performance
Malfunctioning series parallel valves
Incorrectly adjusted or worn hydraulic
pump
Drive valve SVD1 not energized in one
direction
Drive in one
Counterbalance valve CBV1 or CBV2 not
direction only
functioning correctly
No output from GP400
Page 115
Possible Cause
Speed Level Seres - Servce & Parts Manual
Remedy/Solution
Return maintenance lock to the stowed position
Check wiring to lowering valve located on Lift Cylinder
Clean debris, check for damage, replace
Clean orifice/s located inside hose fitting on lift cylinder
Check HELP messages using EZ-Cal
Check lift valve coil
Clean debris, check for damage, replace
Clean orifice/s located inside hose fitting on the lift cylinder
Charge, check charge diode & connections
Test (6-8 ohms), replace
Select Drive position (upper control box), Check switch
Check switch position from GP400 with EZ-Cal (see EZ-Cal ID# 2b-2)
DLD
Check connections at valve
Check Drive Valve for contamination
Check Drive output from GP400 (See EZ-Cal chart ID# 2b-4 & 2b-5
also 2f1-4 & 2f-15)
Check connections at valve
Check Proportional valve for contamination
Check proportional output from GP400 (see EZ-Cal ID# 2f-9 & 2b-3)
Check HELP and MODE message on EZ-Cal
Lower and operate Auto-level
Check HELP messages using EZ-Cal
Check Speed/Torque switch on upper controls
Located on rear wheel motors only
Check electrical by disconnecting valves
Check function by replacing valves
Inspect wheel motors for excessive bypass
Check Speed/Torque switch on upper controls
Check battery voltage with multi-meter or EZ-Cal
Clean, service, charge batteries
Inspect wheel motors for excessive bypass
Located on rear wheels only
Check electrical by disconnecting valves
Check function by replacing valves
Located on top of main hydraulic manifold PD1, PD2 & PD3
Remove and inspect
See Hydraulics section for pump adjustment
Inspect or replace pump
Check 12 volts to appropriate coil
Check coil
Check valve function
Swap counterbalance valves to see if functioning direction changes
Check switch position output from GP400 (see EZ-Cal ID# 4f-7
– FWD or 2f-9 – Reverse)
January 2019