Kubota Zero turn mowers

Coolant capacity & service interval

Kubota Zero turn mowers utilize coolant with a capacity range of 0,25 to 3,8 liters. Service intervals include checks at 10 hours and changes at 12 or 24 months. The data covers 5 configurations.

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

TypeSpecifications
ZD21-EC/ZD21N-EC (2002- )
  • Use: Normal
  • Capacity 2,6 liter
  • Check 10 hours
  • Change 12 months
GZD-15
  • Use: Normal
  • Capacity 3 liter
  • Capacity 0,25 liter (Recovery tank)
  • Change 12 months
GZD-15-IIHD
  • Use: Normal
  • Capacity 3 liter
  • Capacity 0,25 liter (Recovery tank)
  • Change 12 months
GZD-15-IILD
  • Use: Normal
  • Capacity 3 liter
  • Capacity 0,25 liter (Recovery tank)
  • Change 12 months
ZD28-EC
  • Use: Normal
  • Capacity 3,8 liter
  • Capacity 0,25 liter (Recovery tank)
  • Change 24 months

Additional Notes

  • The GZD-15, GZD-15-IIHD, and GZD-15-IILD share identical cooling system specifications, each carrying a main system capacity of 3 liters alongside a 0.25-liter recovery tank, with a 12-month coolant change interval under normal use conditions.
  • The 0.25-liter recovery tank capacity listed for the GZD-15 variants represents a separate overflow reservoir, which is distinct from the primary cooling circuit volume and is not included in the 3-liter main system figure.
  • The Kubota ZD21-EC/ZD21N-EC (starting from 2002) carries a slightly smaller cooling system capacity of 2.6 liters compared to the GZD-15 series, and no recovery tank capacity is listed for the ZD21 models.
  • A 10-hour check interval is specified for the ZD21-EC/ZD21N-EC cooling system under normal use, which reflects a routine inspection frequency rather than a full coolant change, with the actual change interval set at 12 months.
  • The ZD28-EC holds the largest cooling system capacity among the listed models at 3.8 liters, paired with a 0.25-liter recovery tank, indicating a more substantial engine cooling requirement relative to the GZD-15 and ZD21 configurations.
  • The ZD28-EC carries a 24-month coolant change interval under normal use conditions, which is twice the interval specified for the GZD-15 variants and the ZD21-EC/ZD21N-EC, both of which are set at 12 months.

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