IMT 4004i User Manual

Oshkosh Corporation Classification: Unrestricted
Chapter 4 Maintenance & Repair 43
Power Unit Troubleshooting
CAUTION:
AVOID MOTOR DAMAGE! The DC electric motor can overheat. Run for short periods to avoid
overheating. The maximum pump working period depends on the pressure required, but
working periods should never exceed 5 minutes followed by cool down to ambient temperature.
See the technical specifications for pump performance charts and operating intervals.
NOTE:
The pressure relief valve is factory set to 2500 psi (172 bar).
COMPONENT
ISSUE
PROBABLE CAUSE
MOTOR
Motor does not run.
Check battery, battery cables, cable connections, and start
switch operation.
Motor runs hot.
Check voltage. Check motor for worn bearings, burned
wires, corrosion, or water or oil in motor.
Motor overheats.
Check motor size in relation to pump displacement size.
Check relief valve setting. Check for pump damage and
motor damage.
Motor does not run.
Check DC power source. Check motor brushes for wear,
and motor for internal damage. Check pump rotation.
HYDRAULIC
SYSTEM
Slow operation.
Check battery, battery cables, and cold temperature ratings.
Check relief valve pressure.
Runs hot.
Check for pump wear, damage or failure. Check pump inlet
line size. Check relief valve pressure setting.
Lowers too quickly.
Check for defective release valve, defective pressure
compensated flow control valve, and lowering control
device.
Lowers too slowly.
Check for defective release valve and defective pressure
compensated flow control valve.
Load will not hold position.
Check for defective check valve. Check manual or electrical
release valve.
Load will not lower.
Check for defective pressure compensated flow control
valve, manual release valve, and release valve coil.
HYDRAULIC
PUMP
Motor runs but hydraulic system
does not function.
Check drive connection between motor and pump. Check
for pump wear, damage, or failure.
Slow operation.
Check for pump wear, damage, or failure. Check pump
displacement. Check line sizes and relief valve settings.
Short pump life.
Check for contaminated or dirty oil, or wrong oil type. Check
for water in system.
RESERVOIR
Motor and pump run but
hydraulic system does not
function.
Check reservoir oil level. Fill if low.
Slow hydraulic system
operation.
Check reservoir oil level. Fill if low.
Hydraulic oil is too hot.
Check reservoir oil level. Fill if low.

IMT 4004i Specifications

General

Brand	IMT
Model	4004i
Category	Construction Equipment
Language	English