Water-Cooled Diesel Generator Sets-Water cooling system maintenance

1. Daily Pre-Start Checks (5 minutes)

1. Check coolant level

• Ensure level is between MIN and MAX marks on the expansion tank.

• Check only when the engine is cold; DO NOT open the cap when hot to avoid scalding.

2. Inspect for leaks

• Focus areas: water pump, pipe joints, radiator, cylinder block plugs.

• Address any water stains on the ground immediately.

3. Check fan and drive belt

• Fan undamaged, guard intact.

• Belt tension: deflection about 10–15 mm when pressed.

• Replace if cracked, slipping or noisy.

4. Check radiator exterior

• Keep free of dust, dirt and debris to prevent overheating.

2. Correct Use of Coolant

1. Use specialized antifreeze coolant; DO NOT use tap water only

• Tap water causes rust, scale and may crack the block in winter.

• Recommended: Long-life ethylene glycol coolant.

2. Coolant replacement interval

• Regular coolant: every 2 years or 2000 hours

• Long-life coolant: every 3–4 years or 4000 hours

• Flush the system before refilling.

3. If coolant level drops

• Top up with the same type of coolant.

• Rapid loss indicates leaks or a blown head gasket.

3. Key Monitoring During Operation

1. Normal operating temperature

• 75°C – 95°C

• Over 98°C: overheating, stop for inspection.

2. Common causes of overheating

• Insufficient coolant

• Clogged radiator

• Stuck thermostat

• Failed water pump

• Loose or broken fan belt

• Blown cylinder head gasket

3. Overheating emergency procedure

• Reduce load first → idle to cool down

• DO NOT shut off immediately (risk of piston seizure)

• DO NOT open radiator cap while hot

4. Service Life & Replacement of Key Parts

• Thermostat: replace every 2–3 years

• Water pump: replace if leaking or noisy

• Fan belt: inspect every 1 year / 1000 hours

• Radiator: clean externally yearly, internally every 2 years

5. Winter Protection (Anti-Freezing)

• Ensure proper antifreeze concentration when temperature is below 0°C.

• For long-term storage: drain water completely and refill with coolant to avoid freezing damage to engine block and radiator.