Unimog (MB) 421

Power steering fluid capacity & service interval

Unimog (MB) 421 uses power steering fluid with a capacity range of 0,6 to 2 liters. Service intervals occur every 2400 hours or 24 months. The data covers 2 configurations.

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 2 liter
  • Change 2400 hours/ 24 months
U 600, U 600 L (421) (1970-1992)
  • Use: Normal
  • Capacity 0,6 liter
  • Change 2400 hours/ 24 months

Additional Notes

  • The power steering system on the Unimog (MB) 421 carries a fluid capacity of 2 liters, which reflects the volume required for a standard service fill of the hydraulic circuit rather than a full overhaul quantity.
  • The steering box on the U 600 and U 600 L holds 0.6 liter, a notably smaller capacity consistent with a self-contained gear housing that operates independently from the main power steering circuit.
  • Both the power steering system and the steering box share an identical change interval of 2,400 hours or 24 months under normal use conditions, whichever comes first.
  • The hour-based interval of 2,400 hours reflects the working-machine nature of the U 600 and U 600 L, where engine runtime is a more practical measure of service life than calendar time alone.
  • The 24-month calendar limit running alongside the 2,400-hour threshold means that fluid in low-utilization units is still replaced on a time basis even when the hour count has not been reached.

Other Systems