Blog – Heavy Duty Truck Diagnostic Tool

How to inspect and change the oil and filter in the synchronous shuttle gearbox of a JCB bucket loader.How to inspect and change the oil and filter in the synchronous shuttle gearbox of a JCB bucket loader.

April 20, 2026 heavydutydiag 0 Comment

Checking the Oil Level 1 Make sure the park brake is engaged and the transmission set to neutral. Lower the...

How to check and change the coolant in a JCB bucket loaderHow to check and change the coolant in a JCB bucket loader

April 19, 2026 heavydutydiag 0 Comment

! WARNING Make sure the engine cannot be started. Disconnect the battery before doing this job. 2-3-3-5 1 Park the...

How to check the foot brake fluid level on a bucket loader with a rear shovelHow to check the foot brake fluid level on a bucket loader with a rear shovel

April 18, 2026 heavydutydiag 0 Comment

! WARNING Faulty brakes can kill. If you have to add oil to the brake reservoir regularly get the brake...

Caterpillar 320E Excavator A WS Cooling Fan CalibrationCaterpillar 320E Excavator A WS Cooling Fan Calibration

April 17, 2026 heavydutydiag 0 Comment

1. Calibrate Cooling Fan Speed A. Connect the electronic service tool to the diagnostic connector. B. Select the “Service” tab...

Caterpillar 311B Excavator 2LS MID 122 – CID 0168 – FMI 00 TroubleshootingCaterpillar 311B Excavator 2LS MID 122 – CID 0168 – FMI 00 Troubleshooting

April 15, 2026 heavydutydiag 0 Comment

• A charging system component is faulty. • A wiring harness conductor is faulty. • The Product Link is faulty,...

caterpillar 311B EXCAVATOR 2LS Automatic Temperature Control Panel Troubleshooting – 584 and 584HD Forwarderscaterpillar 311B EXCAVATOR 2LS Automatic Temperature Control Panel Troubleshooting – 584 and 584HD Forwarders

April 13, 2026 heavydutydiag 0 Comment

Automatic Temperature Control (ATC) – Fault Codes: (only for 584 Forwarders and 584HD Forwarders) Troubleshooting To display fault codes, depress the ON...

The Caterpillar 311B Excavator 2LS heater control system has almost no, or no, reason for hot airflow to the cab.The Caterpillar 311B Excavator 2LS heater control system has almost no, or no, reason for hot airflow to the cab.

April 12, 2026 heavydutydiag 0 Comment

Possible Cause 1: Blower motor not working. 1. Check the circuit breaker or fuse box to ensure there are no...

Caterpillar 311B Excavator 2LS Air Conditioning System Troubleshooting and RepairCaterpillar 311B Excavator 2LS Air Conditioning System Troubleshooting and Repair

April 11, 2026 heavydutydiag 0 Comment

Refrigerant Line Problems The temperature of the airflow from the evaporator has not decreased or has only decreased slightly. System...

How to disassemble the thermostat, torque converter cooling plate, oil cooler, and oil filter of a Cummins M11 series engineHow to disassemble the thermostat, torque converter cooling plate, oil cooler, and oil filter of a Cummins M11 series engine

April 10, 2026 heavydutydiag 0 Comment

① Loosen the coolant hose clamps, remove the four bolts, thermostat housing, and thermostat (see Figure 2-28). ② The torque...

Caterpillar 320E Excavator AWS Valve Clearance Excessive – Troubleshooting and SolutionsCaterpillar 320E Excavator AWS Valve Clearance Excessive – Troubleshooting and Solutions

April 9, 2026 heavydutydiag 0 Comment

Troubleshooting and Test Steps and Results 1. Lubrication A. Remove the valve cover. Refer to Disassembly and Assembly, “Valve Cover...