725, 730, 730 EJECTOR, 735, 740 and 740 EJECTOR Articulated Trucks Automatic Lubrication System Caterpillar

Automatic Lubrication System Troubleshooting

Usage:

725 B1L

Troubleshooting Problem List

Note: The numbers in this index do not indicate a sequence of importance. The numbers are used for reference only.

Note: When a laptop computer is connected to the control unit, the communication between the control unit and the signal lamp stops. This is indicated by a flashing red LED on the signal lamp.

Problem 1

The signal lamp does not respond when the engine start switch is switched ON.

Probable Cause

There is no supply voltage on pin 1. Refer to Testing and Adjusting, "Electrical System - Test".
There is no ground lead connection with the control unit or with the signal lamp.
The signal lamp is broken.
There is a break in the wiring connection between the power supply and the signal lamp.

Solution

Check the fuse. Replace the fuse, if necessary.
Check the ground connection. Repair the ground connection, if necessary.
Replace the lamp, if necessary.
Check the wires. Replace the wires, if necessary.

Problem 2

The yellow light for the minimum grease level is illuminated.

Probable Cause

The minimum grease level in the grease reservoir has been reached.

Solution

Refill the reservoir. The malfunction warning will automatically reset.

Problem 3

The red light for a system malfunction is illuminated. Immediate attention is required.

Probable Cause

The switch for the grease pressure did not turn on due to one of the following reasons.

The primary grease line contains a leak.
Air is in the system.
The pressure switch is broken.
An O-ring is damaged or an O-ring is missing from the metering unit, the switch for the grease pressure, or the blind plug.
The 5/2 solenoid valve is broken.
There is an internal leak in the metering unit or in the switch for the grease pressure.
The surrounding temperature is too low.
The grease is too viscous.
There is a wiring defect.

Solution

Replace the broken line or repair the line. Then, vent the line.
Vent both of the primary lines and carry out the single test cycle twice.
Refer to Testing and Adjusting, "Electrical System - Test".
Check the O-ring. Mount a new O-ring, if necessary.
Refer to Testing and Adjusting, "Electrical System - Test".
Replace the metering unit or the switch for the grease pressure.
Replace the grease.
Check the wiring and the contacts. Replace the wiring and the contacts, if necessary.
Consult the dealer.

Problem 4

The red light for a system malfunction is illuminated. Immediate attention is required.

Probable Cause

A connected series of 11 identical malfunction warnings in the same primary grease line occurred. 11 malfunction warnings occurred consecutively in the same primary grease line.
A report (minimum level) was recorded and no pressure entered the system when the pump was pumping.

Solution

Push the test button on the pump for at least 1 second in order to reset the report. Locate the cause of the malfunction. Repair the problem.
Refill the reservoir. Press the test button on the pump for at least 1 second in order to reset the malfunction warning. Perform a system test. Bleed the system, if necessary.

Problem 5

None of the lights on the signal lamp are illuminated after 1 minute of operation.

Probable Cause

There is no supply voltage on the display.
The ground lead is disconnected.
The display is broken.

Solution

Check the fuses and the connection of the feeder. Replace the fuse or the connection, if necessary.
Check the ground wire. Repair the wire, if necessary.
Replace the display.

Problem 6

The red light for a system malfunction is illuminated. Immediate attention is required.

Probable Cause

There is no communication between the display and the control unit.
The pump turned off because the pressure switch did not turn on during a sequence of successive cycles.

Solution

Check the gray wire (number 6). Refer to Testing and Adjusting, "Electrical System - Test". The red LED is automatically reset after the communication is restored.
See the cause and the solution for "Problem 3". Press the test button for 1 second in order to reset the malfunction. The pump will remain off if the malfunction is not reset.

Problem 7

Both the yellow light for the minimum grease level and the red light for a system malfunction is illuminated. Immediate attention is required.

Probable Cause

The pump turned off because the pressure switch did not turn. This occurred after a sequence of successive cycles while the level of the grease was at a minimum.

Solution

Refill the reservoir. The malfunction warning is automatically reset after the reservoir is refilled.

Problem 8

There is no lubricant at the grease points and no reports regarding malfunctions have been given.

Probable Cause

The grease interval is too long between applications of grease at the grease points.
There is no supply voltage on pin 3. Refer to Testing and Adjusting, "Electrical System - Test". The clock of the control unit stands still and no pause time counts down.

Solution

Shorten the grease interval with the diagnostic tool.
Check the fuse and the wiring.
Check the reason that the supply voltage does not drop immediately after the machine is turned on.

Problem 9

All grease points contain an excessive amount of grease.

Probable Cause

The grease interval is too short. Consequently, too many applications of grease are being made.

Solution

Lengthen the grease interval with the diagnostic tool.

Problem 10

One or more greasing points contain no grease while the other points receive sufficient grease.

Probable Cause

The secondary grease lines are broken or the lines are squeezed.
The output of grease for the metering unit is too low.
A metering unit has malfunctioned.

Solution

Check the affected secondary grease line. Replace the line, if necessary.
Mount the metering unit with a larger output of grease.
Remove the metering unit and clean the metering unit. Mount a new metering unit, if necessary.