Unimog (MB) 421

Coolant capacity & service interval

Unimog 421 coolant capacity is 15-17 liters. The service interval is 36 months. The data covers 1 configuration.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
U 600, U 600 L (421) (1970-1992)
  • Use: Normal
  • Capacity 15-17 liter
  • Change 36 months

Additional Notes

  • The cooling system capacity for the Unimog (MB) 421 U 600 and U 600 L spans a range of 15 to 17 liters, which reflects a service fill figure rather than a dry overhaul volume, meaning the system retains residual fluid during a standard drain and refill procedure.
  • The 2-liter spread between the lower and upper capacity values across the U 600 and U 600 L variants suggests minor differences in cooling circuit volume between the two configurations, even within the same model family.
  • The coolant change interval is set at 36 months under normal use conditions, placing the service cycle on a calendar-based schedule rather than a mileage or hours-of-operation basis, which is consistent with the working nature of utility vehicles where annual distance traveled can vary considerably.

Other Systems