When an excavator engine runs at high temperature, the belt tension is often inspected first. Incorrect tension affects cooling performance and may lead to overheating.

Here are the standard methods for checking and adjusting belt tension.

Belt Tension Inspection Methods

• Visual and Manual Belt Check

Excavator engines are equipped with alternator belts, fan belts, and air-conditioning belts. Inspect each belt for wear and ensure proper tension for stable performance.

When pressing the midpoint of the belt with your thumb, insufficient tension will cause belt slippage, while excessive tension may damage bearings.

• Using a Spring Scale

Pull the belt with a spring scale and measure the deflection using a ruler.

With repeated checks, operators become familiar with the correct tension by feel.

• Manual Deflection Check (Approx. 6 kg Force)

Apply about 6 kg of force at the midpoint between two pulleys and measure the belt deflection.

The value should fall within the manufacturer’s recommended range.

Belt Tension Adjustment Methods

• Adjusting Through the Manual Hydraulic Pump

Set the manual valve of the hydraulic pump to the tensioning position.

Loosen the necessary bolts and adjust until proper balance is achieved.

• Ensuring Even Load During Tensioning

Rotate the pulley during the tensioning process to distribute the load evenly on the belt.

Once pressure is balanced, tighten the bolts onto the motor base, secure the base, and return the manual valve to the neutral position to release pressure.

• Adjusting by Changing Center Distance

Move the adjustable pulley to modify the center distance between pulleys, increasing or reducing belt tension as needed.

• Belt Replacement Procedure

When replacing a belt, move the adjustable pulley fully inward to minimize the center distance.

This creates enough slack to remove and install the belt.