prime mover smx45 Master Service Manual page 265

Possible Cause
Contaminated or bad
pressure relief valve
Bad lift pump
Bad lift motor
Possible Cause
Bad lift/lower solenoid valve
or wiring
Plugged or malfunctioning
flow hydraulic lowering valve
Contamination in
solenoid valve
Mechanical binding in lift
mechanism
Bad or mid adjusted lift-limit
switch
NOTE: If pump hits relief and lower is attempted, lowering will be slow. Release lower button
momentarily, then continue to lower. Normal lower speed should resume.
Possible Cause
Incorrect lift pressure adjust
Contamination or bad check
valve
Leaking or contaminated
hydraulic lowering valve
Load too large for lift truck
capacity
© BT Prime-Mover, Inc.
Return
Check for contamination in hydraulic fluid. If contamination is present,
flush, fill and bleed the hydraulic system and clean relief valve. If no
contamination is found, replace relief valve.
Replace lift pump (see
Replace lift motor (see
5. Slow Lower.
Repair or replace valve or wiring.
Check for contamination in hydraulic fluid. If contamination is present,
flush, fill and bleed hydraulic system and clean valve. If no
contamination is found, replace flow control valve.
lowering Inspect solenoid for contamination or binding.
Adjust or replace mechanism.
Adjust lift limit switch (see
page 225.) Pump should not hit relief if lift limit switch is operating
properly.
6. Load Drifting/Settling.
Check and adjust lift pressure setting (see
Check for contamination in hydraulic fluid. If contamination is present,
flush, fill and bleed hydraulic system and clean check valve. If no
contamination is found, replace check valve.
Check for contamination in hydraulic fluid. If contamination is present,
flush, fill and bleed hydraulic system and clean hydraulic lowering valve.
If no contamination is found, replace hydraulic lowering valve.
Check load weight. Check lift pressure setting.
Master Service Manual
F-code
PT
Version no
001
Remedy
page 270.)
page 92.)
Remedy
page 221) or replace lift limit switch (see
Remedy
page
2006-08-08
Section C-code
S6.0 6000
Hydraulic System
T-code
SMX
259.)
263